With another fantastic start last week against the Los Angeles Dodgers (the rain-interrupted start in St. Louis last night was an odd bird (9.00 ERA, 0.35 FIP), and occurred after this analysis was completed anyway), Jason Hammel continues to reaffirm the success he had early last season with the Chicago Cubs. On the year through Saturday, he has a 2.65 ERA (3.03 FIP) and has accumulated 2.0 fWAR over 91.2 innings.
Last year, Hammel’s early season success led to his inclusion in the trade with the Oakland Athletics that brought back the Cubs’ starting second basemen, Addison Russell (not to mention rising outfield prospect, Billy McKinney). After leaving Chicago, though, things didn’t go as well for Hammel in the second half. He was a much different, less efficient, less successful pitcher for Oakland, despite his strong results AND peripherals during his time with Chicago Cubs earlier in the season.
Starting with the first half of 2014, we see the numbers that support our memory of his early season dominance. Hammel limited the number of walks (5.3%) and home runs (.75 HR/9) he gave out, while recording a healthy number of strike outs (23.9%) and ground balls (40.1%). Over 96.1 innings of baseball, he had a stellar 2.99 ERA with the peripherals (3.10 FIP and 3.27 xFIP) to support it.
After June 23, though, Hammel made two more starts with the Chicago Cubs and twelve more with the Oakland Athletics. Over those 80 IP, Hammel walked roughly 36% more batters while recording 16% fewer strikeouts and allowing nearly twice as many home runs per nine innings. His groundball rate and BABIP remained nearly identical, but his lack of command and his home run vulnerability were more than enough to spike his ERA (4.05) and FIP (4.91) up over four.
What really burned Hammel in 2014 was a HR/FB ratio that was far greater in the second half (15.8%) than in the first half (8.2%). Ultimately, the combination of more home runs, more walks and fewer strike outs paints the picture of a guy who may have lost a bit of command as the season rolled on.
Interestingly, during his bad stretch, Hammel actually allowed fewer hard hit balls (25.4%) than he did in the first half (35.1%), while also inducing more weak contact (15.8%) than he did when he was getting better results (14.7%). He even had a better LOB% in the second half (79.3%) than the first half (77.3%), indicating that he wasn’t getting unlucky with sequencing.
The good news is that Hammel has been even better in the first half of 2015 than he was at the beginning of last season. Over his 91.2 IP this year, Hammel is striking out more batters (25.0%) and walking fewer batters (4.4%) than he did at any time in 2014. His ground ball rate is still quite strong (39.2%) and he has amassed a 2.65 ERA with even better peripherals than last year (3.1 FIP 3.18 xFIP).
He is giving up more home runs – which we know hurt him in the past – but they are coming in at a much more controlled rate (.88 HR/9). Additionally, his BABIP (.253) may be a bit lower than his career average, but it is not entirely without explanation. In 2015, Hammel is inducing a lot more soft contact (20.8%) than he did in the first half (14.7%) or second half (15.8%) of last season.
Like most pitchers, the key to Hammel’s success is pinned upon control. Over his five starts prior to last night, Hammel’s ERA was just 2.01 ERA. He told Carrie Muskat that the reason for his recent hot streak was better command of his fastball. It might sound obvious, but if Hammel can keep his walks down and the ball in the park, he may have a chance to finish the year as strong as he’s started.