To start the 2009 season the A’s made a somewhat surprising move by bringing both Brett Anderson and Trevor Cahill north to Oakland to start the season. Since they were not only the team’s top two prospects, but also Baseball America Nos. 7 and 11 prospects made this something less than shocking, but both had under 40 innings of experience above A ball. Since the A’s stood little chance of contending, though, they thought it prudent to get their best guys some major league experience. The move worked out in many ways.
While Anderson went on to have a very good year, certainly worth Rookie of the Year consideration, Cahill stumbled a bit. While he did induce groundballs at a decent clip, one of his signatures in the minors, he just couldn’t get major leaguers to swing and miss. Or, specifically, he couldn’t get them to swing and miss with two strikes. He and Brett Anderson shared a 7.4 percent swinging strike rate, which ranked in the bottom third of the league among qualified starters. Yet Anderson struck out 7.70 per nine while Cahill managed just 4.53.
After the season David Golebiewski broke down Cahill’s first experience. While it was written with a fantasy bent, it was an excellent overall look at Cahill’s performance vs. his potential. While David makes a number of good points, I took away three main points:
1) Cahill abandoned his breaking pitches, throwing his curveball 3.4 percent of the time and his slider 6.7 percent.
2) Lefties absolutely murdered him, a .286/.361/.558 line.
3) He feel behind batters more often than the average MLB pitcher.
Those are, of course, in addition to his low strikeout and high home run totals. These concerns were enough, apparently, for the A’s to start him in AAA this season. After two starts they called him up to the bigs, though it looked like he might succumb to the same issues. In five innings against Toronto he allowed eight runs, six earned, against Toronto while allowing three home runs and striking out the same number. A month and a half later, that seems like a blip on the radar. Cahill has been excellent ever since, posting a 3.32 ERA on the season. That’s a bit better than his peripherals, though we have seen some improvement there, too.
Strikeouts have been on the rise for Cahill. He’s had a few low-strikeout affairs — one in 5.2 innings against Texas and two in seven innings against Los Angeles — but he’s also had a few high-K games, including six in six innings against Minnesota and, last night, five in 5.2 innings against Chicago (NL). His current mark is 5.14 per nine, and while that doesn’t remotely approach his minor league rate it is certainly an improvement over last year. It appears to come from pitch selection, as his swinging strike rate, 7.2 percent, is actually lower than last year.
He has also increased his groundball rate, getting it up to 52.5 percent. In fact, in every game since that first one against Toronto he’s induced more groundballs than fly balls, which certainly plays to his strengths. The added groundballs have come at the expense of both fly balls and line drives, which have helped his BABIP and his home run rate. Further helping his home run rate is a decrease in his HR/FB ratio, down to 10.3 percent this year from 13.2 percent last year. That makes for a happy tERA, 4.25, down from 5.39 last year.
Another excellent note on his groundballs: he gets them more often with men on base than with the bases empty. That prevents extra base hits, which in turn prevents runners from scoring. They seem to be poorly struck grounders, too, as his BABIP with men on base is just .214.
Lefties? Not a problem. In fact, he’s pitched better against lefties this season than he has righties. His BA and OBP against numbers are identical against batters of both handedness, but his SLG against lefties, .336, is considerably lower than his SLG against righties, .367. He’s striking out 6.23 lefties per nine innings, and has allowed just two of the 125 he has faced to take him deep despite surrendering more fly balls to them. We’re still in small sample country, so there’s a chance that lefties will catch up to him. For now, though, he’s clearly getting the job done.
Finally, we see that he has altered his pitch selection. In its pre-2009 scouting report of Cahill, Baseball America remarked that, “He backs up his fastballs with a nasty 79-81 mph knuckle-curve, a swing-and-miss pitch with hard downward movement.” They also praised his slider. Yet, as we saw, Cahill did not employ them much in 2009, opting to use his two-seamer, four-seamer, and changeup almost equally. We’ve seen quite a shift in that regard this year. He is now relying more heavily on the two-seamer, throwing it 46.4 percent of the time. Hence all the groundballs. He’s taken a step back with the four-seamer and changeup, and has started throwing that nasty knuckle-curve more often, 12.4 percent of the time. It hasn’t quite worked as an out pitch so far — its weighted value is -0.7, compared to his slider, which he throws far less frequently, at 0.6. But in time I suspect that his increased curve usage will pay off.
To this point in 2009 Cahill has certainly impressed. This article might have been a bit more timely after his previous start, when he downright dominated Los Angeles for eight innings. Last night against Chicago he allowed four runs in 5.2 innings, though his peripherals looked a bit better than that. He still has some kinks to work out — he’s still throwing first pitch strikes at a below league-average rate — but he has still shown tremendous improvement in his sophomore campaign. The kid just turned 22 and could continue along a growth path and justify that No. 11 prospect status. The A’s are starting to see that this season.