Teheran had an uneven season that was a departure from the guy we’d gotten used to over the previous two seasons heading into 2015, but his struggles were generally overstated and primarily confined to a handful of hideous starts. Bill James’ Game Score stat is hardly perfect, but it gives us a general idea of how a pitcher fared in a given start. You want at least a 50 score and anything below a 40 is awful.
He had as many 40 or worse Game Scores in 2015 as he did in 2013 and 2014 combined. Meanwhile, he was in line with output of 50+ Game Scores. To put it another way, Teheran’s five starts of 6+ ER were tied for the third-most with a large group. It should come as no surprise then that as he cut down the implosion outings, he looked more and more like himself. From July on, he posted a 3.23 ERA in 106 IP with just one of those 6+ ER outings on his ledger (an 8 ER demolition at the hands of the Yankees).
Teheran finished with a bang, notching six starts of 0-2 ER en route to a 1.62 ERA in 39 IP with 32 strikeouts. His 16 walks in those starts came in an on-off pattern of 4, 2, 4, 1, 4 and 1. He was able to avoid trouble with the free passes, but it’s something to keep an eye on early in 2016.
His first-pitch strike rate dipped three percentage points to 57%, the 12th-biggest drop from 2014 among the 106 pitchers with 100+ IP in both seasons. Two of three worst months were those final two when he was actually excelling otherwise: 50%, 59%, 60%, 62%, 56%, and 55%. On the positive side, he closed with his best fastball velocity, up at 92.9 MPH on average in September.
One particularly alarming split was his work against lefties. They popped a career-high .893 OPS against him, but it was the second time in three seasons where lefties had a better than .800 OPS. In the two off seasons – 2013 and 2015 – nothing works against lefties. OK, nothing is a little too much. The curve allowed just a .607 OPS in 73 PA, but the fastball and changeup allowed a combined .318/.388/.503 in 601 PA and even though the slider only allowed a .214 AVG in 124 PA, lefties also clubbed 11 HRs (9% HR rate) leading to a .349 ISO and .853 OPS.
The big difference during the successful season against lefties was that he kept the ball in the park, particularly with the secondary stuff. The slider, change, and curve allowed a .200/.212/.330 line in 189 PA with a 27% K, 2% BB, and 3% HR rates. As you might expect, he got to use those pitches a lot more in 2014 than 2013 & 2015 with a 9% difference in four-seamer usage (44% to 53%). And wouldn’t you know it that also ties back to the first-pitch strike issue mentioned earlier. The four-seamer drew a first-pitch strike 65% of the time in 2014 compared to just 57% in 2013 & 2015.
Watch Teheran against lefties early in the count. If he can get ahead with the fastball, he is likely to be successful. If he falls behind, trouble usually ensues. I’m buying Teheran at the discounted rate this draft season as his problem is very fixable and his 2013-14 upside remains in play. He may drop to a streamer-only against righty-heavy lineups if the lefty problem isn’t improving a month, month & a half into the season.