It seemed insignificant at the time, almost unimportant really. After all, acquiring a relief pitcher doesn't create a buzz around the team and make fans buy tickets. But when the Red Sox first year general manager Ben Cherington acquired Craig Breslow from the Arizona DiamondBacks at the 2012 trade deadline, he knew that it would pay large dividends for the future. After all, the Boston Red Sox and Craig Breslow weren’t strangers to each other before the July 31st deal went down. As it turns out, Breslow was once before property of the Red Sox from 2006-2007 as a successful minor league pitcher. But after 6 seasons and 3 different teams, Breslow returned to Boston as an experienced, reliable relief pitcher and has anchored a somewhat shaky Boston bullpen. While relief pitching isn’t exactly an irreplaceable position, Craig Breslow’s performance in the Boston bullpen has pushed that notion to its limits. Unlike most left handed relievers, Breslow has the ability to retire both left and right handed batters which has allowed Red Sox manager John Farrell to expand his usage. In 118 plate appearances right handed batters are hitting just .217/.280/.321, while left handers have hit .265/.315/.422 over 89 plate appearances. As his flexibility and successful platoon splits would suggest, the 33 year old Yale alum has amassed quite a few innings; 51.2 to be exact, which is third most in the Red Sox bullpen. Over those 51+ innings, Breslow has crafted a 2.09 ERA with a 1.14 WHIP. Since the All Star break, Breslow has been particularly “lock down” when entering games; holding hitters to a .192 average and allowing just 2 earned runs over 19.2 innings pitched. But is this the Craig Breslow we should expect to see emerge from the bullpen every time he comes out? After all, he seems to be pitching at or above his career norms. Perhaps a better question is “is this the same Craig Breslow we've already saw?". Baseball, as with any other sport, is obviously very results based. When fans are judging player performance, most of the time they aren’t concerned how a player is reaching their goals, they’re concerned if a player is reaching their goals. Let’s take Craig Breslow for example. As was said earlier, Breslow overall is pitching on par with his career norms. However, one very pronounced area where he has failed to meet his atypical season number has been strike outs. Between the 2008 and 2012 seasons, Breslow has featured a K% hovering from 17% to 25%. However, so far this season, Breslow’s K% has plummeted to 13.5%. Usually when a K% free falls that much it would be normal to see a spike in numbers, or at least some noticeable change. But Breslow has been able to find a way to keep himself on line with his normal season outline. But a pitcher doesn’t simply go from averaging 54 K’s over the previous 5 season’s to throwing just 33 the next. The answer to what changed in Breslow lies in his pitch selection. In examining the left handers pitch selection, two pitches in particular stand out like a sore thumb. Prior to this season, Breslow threw a four seam fastball more than half of the time over his last 5 seasons in the MLB. However, this season Breslow has basically flip-flopped the usage of his four seam fastball and two seam fastball. Numbers show that Breslow has almost abandoned throwing a four seamer by mixing it in just 18% of the time. In its place, he has thrown a two seam fastball 43.5% of the time. This sudden swap in fastball selection seems odd at its surface but if you look back over the course of his career it gets even stranger. Not only did Breslow tend to favor the four seam fastball in the past, but he also totally neglected the fact that he even threw a two seamer. Before this season, the most Breslow ever threw the two-seam fastball in a season was in 2012 when he threw it 11% of the time.
To me there has to be a correlation to a degree between a change in fastballs and a declined K%. Perhaps the fact that a two seam fastball closely mirrors a sinker could hold some relavence. By their nature sinkers are used to induce ground balls. Keeping that in mind, note that since Breslow began throwing the two seamer more in 2012, his ground ball percentage has risen from mid 30% to mid 40%. During that same time period his fly ball percentage lowered from mid 40% to mid 30%. Thus, a declining K% and a revamped fastball selection seems to be contributing to batted balls off of Breslow.
So what does all of this mean? Breslow has been great virtually all season, does it really matter if he strikes out less batters than he has before? In a sense, no, but it's important to understand that all outs aren't created equally. Pitchers will always take a strike out, no matter what the situation calls for. They aren't dependent on their defense behind them and instead are just guaranteed an out. Therefore, the ability to be to come up with a strike out becomes magnified. As for this season, Breslow hasn't been burned by a falling K% and instead has found success in a semi revamped attack on hitters. There's nothing to complain about when it comes to Craig Breslow, but there are areas to keep an eye on.