 When a batter steps up to the plate front at bat one of two things can happen He will hit the ball or he will not hit the ball If he does hit the ball it will lead to something like a ground out a flyout or a base hit If he does not hit the ball that means he's been walked hit by the pitch or struck out something like that We know that the best pitchers the Roy Halladays and Randy Johnson's of the world strike out a lot of hitters and Do not walk a lot of hitters Weaker pitchers do just the opposite the Mike Mollers and Tyler greens of the world Sorry guys walk as many guys as they strike out But when the ball is hit Conventional thinking will tell you that if the ball was thrown by Randy Johnson It is less likely to result in a base hit and if it was thrown by Tyler green good Pitchers are better than weak pitchers regardless of whether the ball is hit or not, but is that actually true? Let's look at what the numbers have to say about our question If a batter is to hit a ball thrown by Randy Johnson Is it more likely to be an out than when that batter hits a ball thrown by Tyler green? Common stats like batting average use all at bats regardless of the outcome We need to only consider a part of the at bats the ones in which balls are hit into play and Luckily the stat exists for that called batting average on balls in play Or Babip for short Because fielder's have no opportunity to turn them into outs home runs are not considered balls hit into play when it comes to Babip Our hypothesis based on what is basically common knowledge over the past hundred years is that hitters who face Johnson would have a much lower Babip than those who faced green Thanks to a site called fan graphs which tracks every pitchers Babip for every season We can test this out pretty easily in 1995 Johnson pitched 214 innings he led the league with a 2.4a e r a and he won the Cy Young award the hitters who he faced had a Babip of 301 In other words 30% of the guys who hit a pitch that Johnson threw reach base safely The other 70% of balls that were hit into play resulted in outs That same season green through 140 innings and had an e r a of 5.31 which was good for a 19th best on the Phillies The hitters who he faced had a Babip of 313 That means 31% of the eyes who hit a ball thrown by green reach base safely Green's Babip differs by just 12 guys out of a thousand so his Babip is virtually the same as Johnson's Obviously, that's a fluke right? I just picked two seasons that I knew would work Okay, let's try it again in 1998 Johnson split time between the Mariners and the Diamondbacks But his season-long e r a 3.28 would have been in the top 10 of either league Hitters who faced Johnson in 1998 had a Babip of 320 Green's 1998 era was not fantastic at 5.03 This was the last season the green pitched in the major leagues But hitters who faced green in 1998 had a Babip of 254 almost 7% lower than Johnson's You're welcome to look at the numbers yourself, but this example is not a fluke Regardless of whether they are a quote-unquote good or poor pitcher the typical pitcher Babip over their career is Between 290 300 as we have seen with green and Johnson most seasons fall outside that range And there's little relation from one season to the next over a career though things tend to average out Take Johnson's career for example, which lasted over 20 years. He had seasons where his Babip range from 247 1990 all the way up to 348 in 2003 That might make it sound like his Babip increased over his career But the season after his highest season Babip in 2003 the following summer it fell back down to 264 which is the second lowest of his career Johnson's career Babip ended up at 291 Meanwhile green pitched for just four seasons in the 90s and his career Babip came out to 289 virtually identical to Johnson's Since this was first discovered by a guy named vorus McCracken in the late 90s People have been just as surprised as you probably are right now And as I was when I first learned it and many people have been trying to disprove it ever since And while it has not been disproven numerous studies have shown that pitchers do have some effect on balls and play I'll be at less control than what we had thought with our original hypothesis Numerous factors play a role on whether or not a ball hit into play will fall in for a hit The quality of the fielder is the size of the park remember home runs don't count as balls in play and the pitcher Groundball pitchers do tend to have lower Babips The biggest factor though, which tends to be frustrating for a lot of people appears to be luck Sometimes a batter will hit a line dry absolutely drill the ball Right into the glove of the shortstop Other times the shortstop is two feet to the left and the ball flies into the gap for a double The difference between those two scenarios is basically luck possibly. It's good positioning by the shortstop, but But from a batter's perspective, it's basically luck Now if you or I were to walk out onto the mound during a major league game and start a lobbying the ball in there We would probably have a higher Babbit than 300 But perhaps it's not as high as we would assume think about the home run derby If you were to put a normal defense behind the home run derby pitcher Who's throwing the ball exactly where the batter wants it? The batter would have a very good batting average for sure, but he would still be put out plenty of times So the next time your favorite pitcher gives up 10 hits in a game. Remember, he's probably not bad or likely He's just having an unlucky day