Hammel’s first 16 starts were stellar. He logged 102.2 innings as struck out 104, walked only 18 and limited batters to a .208 average. The peripherals were fantastic as he posted a 2.89 ERA/3.14 FIP/3.29 xFIP to go along with a 9.12 K/9, 1.58 BB/9 , 5.8 K/BB and 0.96 HR/9.
His first half was so solid, Joe Maddon made a case for Hammel to be included on the All-Star Game roster — and it wasn’t really a far-fetched idea.
Unfortunately, things began to unravel for Hammel after a hamstring injury forced an early exit during his July 8 start against the Cardinals and he never seemed to get back on track.
Hammel made 14 starts in the second-half and saw a sharp decline in efficiency. He posted a 5.10 ERA/4.10 FIP/3.77 xFIP, saw his HR/9 jump to 1.61, BB/9 climb to 2.96 and opponents average rocket up to .283 in 67 innings of work.
It is of no coincidence that the decline in effectiveness came with an increase in hard-hit balls. Hammel yielded a 28.1 percent hard-hit rate in his first 16 starts, but spiked to 38.8 percent after his return from injury.
Looking at PITCHf/x’s data via FanGraphs, the most noticeable difference was in Hammel’s fastball and change-up effectiveness.
There wasn’t much difference in usage. During Hammel’s first-half run of success, he used the four-seamer at a 39.3 percent clip and the two-seamer at 14.1 percent. After his return from injury, the four-seamer was used at 38.9 percent, while the two-seamer was at 13.7 percent.
However, pitch effectiveness was another story. Specifically, when it came to commanding the fastball and change-up.
Browsing through the PITCHf/x pitch values, Hammel’s four-seamer went from a 3.1 wFA to a -10.5. Two-seamer value dropped from -2.2 to -5.5. His struggles with the change-up didn’t help matters any.
Hammel threw the change only 3.7 percent of the time in his first-half starts, but it garnered a respectable 2.3 wCH. His change-up saw a slight up-tick in usage (5.1 percent) but also saw a decline in value (-1.3).
His slider was his constant as it was his most effective pitch in the first half (9.6 wSL, 37.5% usage) and in the second half, though it was not as effective (5.6 wSL, 33.3% usage).
It is also interesting to note that Hammel nearly doubled his curveball usage (4.6% in the first half, 8.7% in the second half) but didn’t see much change in pitch value (0.0 first half, 0.4 in second half).
It is interesting to note that Hammel’s first-half numbers were similar to what he posted before being dealt to the Oakland Athletics.
Sometimes it gets lost in what Jeff Samardzija did with the Cubs, but Hammel pitched his way into being a key cog in the deal that brought over Addison Russell (among others) as he pitched to a 2.98 ERA/3.91 FIP/3.22 xFIP with quality peripherals that included an 8.61 K/9, 1.90 BB/9, 4.5 K/BB and 0.83 HR/9 in 17 starts.
Couple his second half struggles with pitching a total of 4.1 innings in two postseason starts and allowing 11 of the 25 batters he faced to reach and seven runs cross the plate in the process, Hammel could definitely use some time off the mound. Perhaps more time to get over the midseason injury will help get him back on track heading into 2016.