 We met actually not in Australia. We are both from Australia, but we met here in Bangalore one and a half years ago And we were in a conference and we met by the pool We we started to have a conversation and we had a lot, you know a large number of beers and Under an undefined number of beers. We decided that oh why not why not let's let's talk together and let's let's have an idea that we can we can go on a journey for and Or journey was around what is the ideal number of team members and after like probably we had about 10 beers Decided that's that seems like the perfect number Maybe that magic number is 10 like that, you know, it probably matches the scrum guide. It would be in that range So we thought yeah, let's let's try to prove it that 10 is the magic number and in every team we should have 10 people and So what we decided that not just look at scrum and all the stuff that you know But we we looked a little bit of everything else and we started with history so I went on to Google and Wikipedia and did my older research about what happened back in the paleolithic times and What I find in the middle of middle paleolithic, which is about 30 to 300,000 years ago they were already forms and the forms the smallest unit of the of a team was a family and And families, you know, they had varying numbers, but they actually formed together what they called the bands and in these bands There were 20 to 100 people maximum But when there was a lot of abundance a lot of resources or they had, you know mating or or big celebration They formed the macro bands or a couple of bands got together. It's their version of scaling. I guess and The other thing what is interesting we is it's not just the number is the roles So what you found that in these tea in these families and in these bands? Everyone was like the T-shape. They were all cross-functional, right? So they didn't have their own. This is my task. I'm hunting you gathering Everyone had the minimum skills for survival So everyone if they are alone they could survive on their own for a while The other thing was where they're interesting and it resonated with the holacracy that we learned They actually didn't have a leader. They didn't have a chief So communal consensus was the form of decision-making back in the Middle Paleo Paleolithic so coming closer Then I experimented with sorry. I checked the Roman army and with the Roman army Well, first of all in ancient Rome They formed tribes and the tribes were about a thousand people and it was held The leader of that so they had a leader called the tribe union and they had centurions around a hundred people and Decuries and then I said yeah, I found the answer It's ten because the decade is the smallest unit had held by it led by the Curio is ten people So the Romans must have known it I thought But then I had a look at the army and the army has they had 30 legions and in every legion they had 5,500 people and the form it was very similar So it was it was led by one person and they had so-called cohorts and in one cohort they had so they had ten cohorts and Ten again ten. What a surprise, right? 30 legions, but in each of the legions they had ten cohorts and cohorts had about so they had I think 480 people nine of them and one was a special cohort with with Think let me check 800 people just to make sure the numbers match up and in the cohorts they had Centuries with 80 men and and that was kind of their smallest unit Then I thought okay, so at least I could find some, you know evidence for ten people and not ten people I had a look at ancient Japan and Ninjas, you know ninjas they work usually alone But sometimes they form teams, but it was never more than probably four people because they had to be you know When they when they got in somewhere to kill someone they cannot be many So they they were very much focusing on small teams very small teams quite often just one person On the contrary summarize are like the scaled version of ninjas They this is their formation. So in in in this in calls honjin Sonaya They had over a thousand fifteen hundred people fifteen hundred people with all different roles So what you can see here? Let me just show you here So these are completely different units with strictly defined roles, right? So it was it wasn't cross-functional everyone know exactly what they had to do there were archery They were cavalry there were there were people with spears a spear units and standard units So I thought okay, I just cannot seem to find an answer. It seems that you know one person team 1500 person team. They are just work fine. So I looked at something that you might be more familiar with the Indian army and I I'm not as specialist in here. So please if I'm wrong just I'm happy to fail It's okay. My my source is Indian army dot and I see that I am but what I found here is the smallest unit It's called a section and how many people in the section. What do you think Alex? I would say ten because that's the perfect number Absolutely, right. So absolutely right and they are led by a section commander and they go up to platoon So there are three section in the platoon so about 30 people and then you go into a rifle company another three So it's 90 people and then you go into the Italian which has four rifle companies. So that's 360 people if I can't correctly I didn't continue the numbers because it just became too large and I couldn't count And I thought okay the answer must be ten right what does spirituality say Alex? Well, he started to study the history and how the Paleolithic times the tribes the Roman legions the samurai the ninja So you started to get into human history, but beyond human military history There's also spiritual history that proves ten is the perfect number The ten commandments here. We have the ten startup commandments, but once again the perfect number is expressed in a variety of religions Christianity it's not just expressed only in Christianity, but in a variety of other religions as well Sikhism Ten that's right There's ten gurus. I believe it is right. These are the ten gurus here again another part of the world another culture Not even connected in Terms of like basis for the formation of the religion, but once again coming back to that human principle That essence that ten is the perfect number And it's reflected in a variety of ways across our religious landscape Tithing which is a concept of donating to your religion was traditionally ten percent of your income So whatever you earned you gave ten percent to your church whatever that church may have been once again ten commandments ten gurus Ten percent of your income to support your religion and it's not just in established Large Established religions right it's also a numerology and other aspects spiritual aspects of our society Here's how it's reflected in a variety of different ways in our societies ten Is considered to be a spiritual number it has Numerological significance in a variety of cultures These are just some of the words that describe what the number ten meant to ancient cultures like the Greeks and the Romans and the Indians and the Chinese it's all about Karma and perfection and harmony It was even in significant in the ancient civilizations of Mesopotamia and Egypt and It's not just in spirituality and religion and the military and Historical significance is also reflected today in sports Which I guess is kind of the whole human band thing again, right? Yeah, and and what we did is how does how our sports informed and what are the roles there because the perfect number We all know now it stands so we had a look to prove it in the area of sports Now there are 750 sports played around the world's and more than 200 are actually recognized by a national or an international Federation and while individual sports are very popular So our team sports, so I had a look at the team sports And of course if I come to India I had to look at cricket course and I didn't know cricket So I watched La Gan which hopefully you are familiar with and what I found It's an almost perfect sport because it has 11 players. That's close to perfect. Very close Yeah, very close and you all know the rules So one team is bowling the other team is betting and what I what I learned here is that actually skills are pretty important So have you seen this movie by the way? All right, so you remember boob on Amir Kani is like the main character But there are and he's good at everything so he's truly seems like a cross functional leader of the team But there are others like Kashra who is a fantastic spinner and he has I think the only hat-trick in history Well, it's in the movies, so But he was not very good at betting But he did a hat-trick so he was very he has very very special skills in that yeah, and that held against the English But when I look at another Indian sport Kabadi Maybe it's not as perfect because it's seven players in each it's close though It's close. It's close. Yeah, and and you have a special role there as well a writer and By the way, anyone supports the Bangalore Bulls? Well, you know they are champions. They are pretty good I only watched a couple of matches just to make sure I'm coming prepared That's not just BS through the whole you know like a body But it's a pretty interesting sport and and then again showed that how important that you have a team Who are actually trying to? Trying to fight against the Raider here Had a look had a look at a couple of other sports And and then I I thought okay the perfect number the perfect sport must must be across and softball because they have 10 players Yeah, yeah, that's a perfect number after all. I think so Yeah, I think if you take one person out of cricket, could it be the perfect sport? It might be it's a perfect sport anyway, right? And then then I had a little cookie. Maybe maybe maybe sports Maybe that's 11. I have to be more precise. I have to look at some other things Yeah, let's have a look at nature, right? What happens with animals? Do they form a team of 10? What do you think? Yes, of course, of course So Wolfpack is is a perfect example You see different numbers here. They are from two different sources So one of them said that most of them have six or seven them members, but can go up to 15 They are said five to 11 Sometimes with huge packs of 42, right, but 10 probably is in that range So must be still the perfect number four packs of 10 perhaps four packs of 10. That's right What was what I also found fascinating is the roles within a wolf pack So you have you read Elia who gold rats to go? So you remember in when they go on a on a journey and herbie is kind of the slow kid and Everyone that they cannot form a line and they realize the slowest person must be at the at the line at the start of the line So wolves know that they didn't have to read Goldred's book They actually have the oldest and slowest wolves in the start of the in the front of the Wolfpack So they set the pace. It's not the fastest. It's the slowest setting the pace Right, so they are always together and the leader is actually in behind so making sure that the alpha male Sorry alpha Alpha yeah the nominate leader of the pack stay behind so actually that wolf is kind of caring for the others protecting them And I found it very fascinating this one has more than 10 wolves So it's probably not the perfect back. Yeah, because I think 10 is still the perfect. I would agree with you and then I read about the Bengali tigers and They are endangered species probably because they don't hunt in packs of 10. They do it alone They lead solitary lives and they hunt individually. So Only some of the female tigers actually can cross territory, but only for mating purposes So they they are they are they don't form teams of 10 if I would be their consultant Maybe I would come form form pack to 10 and I would suggest yeah, right and be cross-functional. I don't know, right Sorry, I'm just making that up Indian elephants they actually living in herds and the herd can consist to from 8 to 100 individuals So it's often you see 10 10 bachelors elephants together, right? So I think does that really support I think so it doesn't make sense. Okay, so it's Wolf can be two packs of 10 tigers cannot be and they are endangered but elephants can be packs of 10 to it Must be the perfect number. I would agree. In fact, it's the same things expressed in ants and not only ants but robots Researchers have discovered that in large ant colonies and also in Situations where robots are used they'll maximize their potential in about teams of 10 So you can't have more than 10 ants at the same time in a tunnel digging the tunnel And it's the same for robots as well. If you're familiar with Roombas and other Robots that clean houses and stuff like that if you put a hundred Roombas into your house It wouldn't be efficient at all, but if you had like around 10, that's when you get the maximum efficiency. So ants wolves Elephants robots not just nature, but I guess artificial intelligence all seems to agree that 10 is the perfect number and It's reflected in other ways Across our universe in society Our numbering system is the decimal system, right? We have 10 fingers on our hands and all our numbering systems are based on 10 used in society Here's the original numbers from Arabic, right and then the Roman numerals that we're familiar with in Western society The metric system based on 10 Most of the countries in the world use the metric system based on 10 10 the perfect number just seems to make sense It's reflected everywhere Money right money most units today are based on 10 once again the decimal and In science now this is where we get into some real hardcore stuff The war because now we're gonna get into the stuff that reinforces all these observations that you and I have made, right? We've talked about the military history spirituality religion What happens in nature, but there's actual research that actually reinforces all of this stuff and Mostly centers around this number. This is known as Dunbar's number. So what is Dunbar's number? Dunbar's number is the generally accepted number of the maximum Efficiency of a tribe of human beings which is around a hundred and fifty people Generally, most researchers would say that there's a range between 100 to 250 with the optimal number being a hundred and fifty So you might have heard of Dunbar's number before so where does it come from? Okay, so what happened was a researcher named Dunbar was trying to figure out The maximum or the most efficient size of primate tribes. So what are primate tribes? They're like apes and chimpanzees and monkeys and he's a researcher who thinks about How do we develop social skills? so he went out into the wild and all these remote locations and he studied chimpanzees and primates and apes and Observe them and what he discovered was that these tribes of primates tend to kind of form around groups of a hundred and fifty Primates and why was that the what why was that so? It's because they don't have natural language. So a hundred and fifty primates is the maximum number of primates that can get together in a group and survive Because the other part of their time besides surviving is from grooming You know how we groom in scrum or refined in scrum. Well, that's not the kind of grooming he meant he meant like This kind of grooming, you know, we like groom stuff off your thing Right, so when you have more than a hundred and fifty primates, they spend so much time grooming that they actually can't survive They starve to death So he then applied this mathematical formula, which he observed different primates along and he discovered that humans Actually have the maximum efficiency rate of around 10 people The reason humans can go down to 10 people is because they've replaced physical grooming with language so language or otherwise known as gossiping is The human form of social grooming and if you take that mathematical formula He discovered that about 10 people is the perfect number of people in a human tribe Where they can be maximally efficient and yet still gossip about each other So you see this reflected in other ways in in sympathy groups that form in animal tribes They'll also have communication techniques that maximize around 10 to 12 individuals And if you apply Metcalfe's law to it you may have seen this before it's about communication pathways You take the number of people on your team And you multiply it by the number of people minus one on your team divided by the people on the team Ten is essentially the perfect number where you get the maximum potential amount of communication on a team of humans Without going too far up the scale So there's science behind this board. It's like a real thing When I you when I organize my birthday drinks, it's always around 10 people exactly And in fact, there are there's other research out there that says Even though 10 seems to be a perfect number This particular research says that for high impact groups. It was somewhere around six Which I guess is more in line with the the ninja groups, but I'm still going with 10 is the perfect number Close enough And in fact, if you've ever played tug of war, there's the wringleman effect What that says is you as you add more people to a team They actually become less efficient and do less work Because there's more people to do the work each individual does less work once again Around 10 people is the perfect amount of people on a team where they do the right amount of work And you maximize your efficiency and how does this relate to agile? Of course, you're familiar with these ones, right? So if you look at XP XP has these seven roles. So my research is here is Wikipedia but But what it says Wikipedia said that XP only works on teams on 12 or fewer people, right? However, it suggested that one way to Go go against this limitation is to break up the project into smaller pieces and and to to have smaller groups and Similarly scrum you're familiar with scrum talks about like having one product on there one scrum master and the development team of Three to nine people which is if I add them up together. It's like seven to eleven, right five to eleven. Yeah Where ten is ten is between five that's right. And it's between five to yeah, yeah, absolutely and So because if you have more than nine members on in the teams, it requires too much coordination But if you have less than three then, you know, you don't have necessary all the skills required, right? What does safe say safe say pretty much the same thing? So if you look at scale the job framework it talks about an agile team of five to eleven people that's including product owner and scrum master, right? DSDMA turn anyone heard of DSDMA turn Yeah, no one ever. No one ever I have a certification in it and I never used it But it has 12 roles and and if I add up the numbers I played around with it You have to have somewhere between five to twelve people in DSDMA turn in a team as well So I think ten is still a good number. What do famous people say about this Alex? Well, Jeff Bezos from Amazon in Seattle essentially says that teams should be two pizza two pizza teams now You might not want me on your two pizza team, right? I can eat a whole pizza I'm sure you can't do but still right. It's about two slices per team member, right? I suppose if you're a responsible pizza eater, it's probably around ten people Troy McGannis at Agile 2018 in San Diego last year was talking about Large teams and it kind of stirred up a little controversy He was a keynote and he suggested that large teams were a way you could handle dependencies Because you could have more people on the team handling sections of the value stream And it was quite controversial because most Agilists tend to agree that around ten people is the perfect size for an agile team Talking to Chet Hendricks in back in 2015. He said that in every team of 100 people There's a team of 10 waiting to get out because a team of 10 people can actually accomplish something while a team of 100 people won't Jim Benson the inventor of personal can ban 10 people the perfect number where introverts on the team don't necessarily have to talk to other people on the team But more interestingly enough Jim Benson said this after he said the the next thing after he said this A small group can accomplish anything, but a large group can only talk about accomplishing almost anything Right, so even the leading luminaries in our field seem to agree that 10 people is the perfect number for the For the number of people in a team before I Still agree So what what do you think the perfect? What do you think the perfect team size? I'm not sure anymore. I mean we talked about all the time about Perfect team size of course. Yeah, if you take common sense, I don't think there is a perfect team perfect team size Are you sure about that? I put it up there on the slide. I wrote that so there is no Yeah So is there a perfect number? I don't think so. I don't think there is a perfect number. Is there a perfect recipe? I don't think there is a perfect recipe for any team and is there a perfect methodology a perfect framework for whatever team There is no there is no silver bullet. We talk about 10 people, but there is absolutely no perfect number Yeah, there are more important things that numbers First of all Understand that people are complex, right? So we move in a complex here There is no best practice even no good practice if you take Kinnabin Kinnabin suggests you probe you sense and you change So you try things You get the feedback and then you change based on the feedback It's important still to have a reasonable number Number of people on the team is ten a reasonable number. I think it's a reasonable number So it may not be the perfect number the solution to everything, but it's a reasonable number I think it's still a reasonable number. Have you worked with teams over 20 people? Yeah, house communication. Did you have your 20 best friends? No, you cannot and and I just had a chat with Shane hasty and he told me that I think there is there are Cross-functional people of 70 people and it's working fine. I've never seen anything You know over 15 is getting very very difficult. So I think having thinking through the reasonable number is still important right and What you talked about the tug of war what is important if you add more people to the team It will not lead to better performance Right if you if you are in project management or if you are working and you have deadlines quite often what happens people just say Oh, let's have more resources That will not solve the problem. In fact, it actually gets worse most of the time It changes the culture of the team. So as soon as you add someone in with new skills, even if the person is a nice person it changes the whole culture of the team and When you talk about what is important in a team dynamics, it's a lot more about trust. So Taking away people or adding people will change the trust and it will change the team dynamics and If you've seen Margaret Heffen and Stokes about super chickens if not just Google it and go into Ted She refers to an MIT research where she had there are three things that most most highly performing teams have they have No dominant voice and there that means also that there is no free right They have high EQ and they have more women on their teams And of course you're familiar with Google's project Aristotle Okay, so if you're not familiar that was a couple of years ago Google did a research on its 180 teams internally What give what makes the highest performing teams high performing and they had their Theories that it probably the high IQ or or certain attributes But what they found it was a lot more about social norms that made those teams high performing And they found five key things and the number one things that you probably heard because it's it's a bit of a buzzard But it's the most important things is having psychological safety within your team And that is if can we take on the risk? Can we take on risk in this team without feeling insecure feeling embarrassed? Right if you think about you have a good idea and your manager you are you have the risk that I better Don't say that you don't have the psychological safety, but high performing teams people have that The second one was dependability. Can we count on each other? If I if you say that you will do things will you do the things or will you not? The third thing was structure and clarity our goals roles and execution plans are clear and again I could resonate with the holacracy. I know what I'm responsible for and I know what you're responsible for And we know that we can count on each other And of course meaning of work and the impact of the work Are we working on something meaningful that will make a difference or do we fundamentally believe in what we do matters? Those were the five things that Google found you think this is more achievable in a small team context before Team of 10. Yeah Maybe Maybe yes, but whatever team you have don't forget these five things What you need to ask is what is the goal of this team? Why are we why am I building this team? Why am I creating this team and what are the skills needed and what type of the people are needed to address all the required skills Rather than just a number. So maybe magic number is not 10 There are more important questions. That's what I found. Yeah Well, thank you for attending today. This is the link to the presentation. So the link to the presentation is in the presentation We will share this later. So Feel free to go check it out. This was this kind of represented our our journey of research, right? Absolutely. Yeah, and ten beers at least and and and of course if you want to have a couple of beers Maybe ten beers tonight with us. We will be here. Yeah, of course Thank you. Thank you. Thank you very much