Top 5 SwStk% Decliners by Mike Podhorzer September 5, 2011 On Saturday, I looked at the top five SwStk% risers, so today I take a gander at the opposite end of the spectrum: the decliners. Whether due to a loss of velocity, change in pitch mix, a mechanic change, or randomness, fewer swinging strikes is usually a bad sign. After never posting a K/9 above 8.6 in the minors, it was somewhat surprising to see Jhoulys Chacin end his time with the Rockies last year with a 9.0 mark. That strikeout rate was actually legit though given his 10.8% SwStk%. This year, though, his SwStk% has fallen to just a tick below the league average, despite showing the same velocity and throwing his fastball at the same frequency. He has thrown more sliders at the expense of his curve ball and change-up, but his PitchF/X data tells us he is getting fewer swinging strikes on the curve and change-up. I guess it’s a good thing he has thrown more sliders, otherwise his SwStk% may have dropped even further. Given his rather pedestrian minor league strikeout rate, his current level seems closer to his true talent than the batter per inning from last year. The only reason Jered Weaver finds his name sitting second on this list is because last year his SwStk% jumped to 11.2%. Previously, it had always sat between 9.0% and 9.9% (with an 8.1% thrown in during 2007). Given the slide he has experienced this season after last year’s surge, it seems clear now that last year was the outlier. With the exception of a bit better control, Weaver is pitching almost exactly the same as he always has, aside from last year, though major luck is making many think he has having a career year. Sure, the results on the surface suggest it, but this is the same old Jered Weaver. Seriously, Kevin Correia made the All-Star Game, right? Too Funny. His SwStk% is at a dangerously low mark, especially considering his GB% is barely above the league average. There were times in his career where he teased us with some interesting skills, but he may be a lost cause. Jon Lester has seen his SwStk% drop below 10.0% for the first time since 2008, while his strikeout rate has followed suit, dropped below 9.0 for the first time in that time span as well. After surging from 2008 to 2009 and maintaining nearly all of his gains, Lester’s average fastball velocity has dropped back below 93.0 miles per hour. Looking at the PitchF/X data, he is getting fewer swings and misses on his curve ball and has also thrown his sinker more frequently, which has generated whiffs at just a 2.3% rate. That pitch will induce more grounders, but obviously is not going to be the best pitch when it comes to punching out hitters. Lester could see his SwStk% jump back up again if his curve ball returns. Though Jair Jurrjens‘ is enjoying the second season of his career with a sub-3.00 ERA, things aren’t looking as rosy under the hood. A 5.3 K/9 with only good, but no elite, control and just a league average batted ball profile is not a recipe for long-term success. Boasting a SwStk% below 8.0% for the first time since his rookie year, and an average fastball velocity down 2.0 miles per hour from last season, it is really quite an achievement he has managed to keep his ERA below even the 4.00 level. It is clear that his knee has been bothering him, especially in August, but he is someone I would want nothing to do with on my fantasy team next season.