The first pitch is critical against left-handed hitters.
The biggest factor leading to Kevin Siegrist’s reverse splits is the first pitch. The reliever must improve his first pitch execution if he is to succeed for the St. Louis Cardinals.
The importance of a first pitch strike is hard to overstate. In 2016, considering only pitchers with 10+ IP, pitchers allowed a .622 OPS after throwing a first-pitch strike compared to an .825 OPS after missing with a first-pitch ball.
When comparing these splits to the sampled pitchers’ overall OPS against of .749, they were 16.9% better after throwing a first pitch strike and 10.3% worse after a first pitch ball. Clearly, the first pitch is critical for nearly every pitcher.
When looking at Kevin Siegrist’s count splits, however, we see an important distinction. Following are Siegrist’s stats through an 0-1 count versus a 1-0 count, split by batter handedness.
When Siegrist gets ahead with the first pitch against RHH, he has held them on to a .532 OPS. When he falls behind with the first pitch, he has allowed an OPS of .648. This difference is mostly attributable to his 18.1% walk rate after falling behind, compared to only 4.9% upon getting ahead.
In any case, a .116 difference is barely more than half the league average OPS difference of .203. Siegrist remains effective against RHH even after falling behind, which allows him to limit the damage these hitters inflict.
Against LHH, however, there is a much more significant difference. When Siegrist gets ahead in the count against lefties, he has limited them to an average OPS of only .463. This is actually better than his line against RHH, leading to a “normal” split after an 0-1 count.
When he falls behind, though, LHH have an .893 OPS against him. This .430 difference is more than twice the league average of .203 and is the obvious driver behind Siegrist’s overall reverse-splits.
Additionally, Siegrist is especially potent against RHH when he is ahead, striking out 41.1% of RHH when he gets a first pitch called strike. Against LHH, his K% in the same situation is significantly worse.
Furthermore, Siegrist has struggled with walks even when he gets ahead of LHH. This is an obvious indication that, for some reason, he lacks control against lefties. I will explore this topic shortly.
Unfortunately, Siegrist continually puts himself behind in the count more often against LHH than RHH. The table below shows Siegrist’s called first strikes as a percentage of non-batted first pitches (that is, those taken for strikes, balls, or swung at and missed, or fouled off for a strike).
For whatever reason, Siegrist clearly struggles to get ahead in the count against LHH. He has never thrown first pitch strikes to even half of LHH batters faced in a season, and has been more than 10.0% worse against LHH than RHH in three of his four seasons. The smaller difference in 2016 resulted more from his struggles to locate the first pitch against RHH than progress against LHH.
Consequently, Siegrist is behind in the count to LHH more often than against RHH. Without a dependable or effective off-speed pitch to feature against LHH when behind, he struggles. The end result is that Siegrist continually puts himself in the situation where he is least likely to succeed, due to both his location problems and repertoire.