Coming out of spring training, the story surrounding Masahiro Tanaka was about his fastball. Tanaka, with his partially torn UCL, said his average velocity would be down in 2015, with more (slower) two-seamers and fewer four-seamers.
According to data from Brooks Baseball, in 2014 Tanaka's four-seam fastball averaged 94 mph, his two-seam 91 mph. He also used his four-seam fastball slightly more than his two-seam: 426 to 389.
The news of the change in strategy was surprising. It didn't make a ton of sense to me to change course. And it appears Tanaka is having second thoughts as well.
Tanaka's fastball data from his four starts in 2015:
| Start | Four-seam Count | Two-seam Count | Four-seam % | Four-seam whiffs | Two-seam whiffs |
| 4/6 | 5 | 22 | 19% | 0 | 0 |
| 4/12 | 21 | 21 | 50% | 0 | 0 |
| 4/18 | 25 | 12 | 68% | 1 | 0 |
| 4/23 | 24 | 18 | 57% | 2 | 2 |
Tanaka's maximum velocity on his fastballs are still down a bit from 2014. In his last start at Detroit, though, he saw top speeds of 94 on the four-seam and 93 on the two-seam fastball. Considering game-time temperatures of 33 degrees in Detroit, those numbers are encouraging.
Tanaka is slowly getting back to his fastball strength, a more balanced mix of four- and two-seam fastballs with good command. I never liked the idea of heavier use of his two-seamer, and it seems that he's realizing the same.
