Masahiro Tanaka
Bruno Rouby, ESNY Graphic

New York Yankee starting pitcher Masahiro Tanaka’s recent struggles can be boiled down to his ineffective fastball. 

The New York Yankees have had major issues with their starting rotation this season. Masahiro Tanaka‘s performance this season has been one of those glaring problems within the Yankees’ rotation. The 30-year-old is currently pitching with a 4.56 ERA, 1.240 WHIP and a 4.52 FIP through 25 starts this season.

Specifically, Tanaka has performed even worse since the beginning of July. Through eight starts since the start of July, Tanaka has recorded a 6.35 ERA, 1.370 WHIP, 5.44 FIP, 1.99 HR/9 and a .274 OPP AVG.

Those horrific results are large in part because of Tanaka’s ineffective fastball since the start of July. Tanaka’s fastball was one of his best pitches during the first two months of the season. His fastball was utilized 27.6% of the time and batters hit a .240 AVG off it.

Tanaka also produced a 28.3% strikeout rate and a 22.6% whiff rate with his fastball during that time as well. However, those positive results started to disappear during June, which then set the tone for what was next to come for Tanaka’s fastball.

Through five starts in June, Tanaka threw his fastball 30.3% and surrendered a .364 OPP AVG, .409 SLG and a .491 XSLG on his fastball. The two-time All-Star also generated just a 4% strikeout rate and a 15.75% whiff rate on his fastball as well.

Things have continued to get even worse for Tanaka and his fastball since the conclusion of June as well. This has earned him those troublesome numbers since the beginning of July. Through his five starts in July, Tanaka unsurprisingly threw his fastball at a rate of 23%. But, the reduced usage of his fastball has only lead to more disappointing results for Tanaka.

Tanaka gave up a total of five home runs off his fastball in July and recorded a .414 OPP AVG, 1.000 SLG and a .812 XSLG. While Tanaka did see his strikeout rate climb to 16.7% and his whiff rate to 20.7%, that couldn’t out way all the other damage he surrendered.

The Japanese-born pitcher has done a better job of giving up less hard contact during his three starts this month. But, he’s still been taken deep far too many times and has seen his strikeout rate and whiff rate drop significantly once again.

Through three starts this month, Tanaka has allowed three home runs and has created a 10% strikeout rate and a measly 2.8% whiff rate. Tanaka has also increased his usage of his fastball this month to 30.9%. But he still hasn’t seen results similar to the first two months of the season.

Tanaka has also thrown his fastball all over the strike zone throughout this season as well, which has played a large part with why he’s given up so many home runs and hard-hit contact this season. Tanaka did a fantastic job keeping his fastball out of the middle of the strike zone during the first two months of the season.

Here’s where Tanaka was throwing his fastball from the beginning of the season to the end of May:

However, Tanaka has done a terrible job of that since the beginning of July. This certainly explains why he’s given up so many hard-hit balls and seen his strikeouts rapidly decline on his fastball.

Here’s where Tanaka threw his fastball during his starts from the beginning of July to his latest start against the Cleveland Indians:

Thankfully for the Yankees, it shouldn’t be too hard for Tanaka to correct himself. Tanaka has been very successful with his other pitches this season. He’s thrown his slider the most out of all his pitches this season and has recorded a .187 OPP AVG and a .344 SLG.

Tanaka has also produced an impressive 27.6% strikeout rate and a 33.6% whiff rate with his slider this season as well. His splitter has also been extremely effective since the start of July. As Tanaka hasn’t surrendered a home run off his splitter since June 22.

So, Tanaka just needs to command his fastball more effectively during the rest of the season to correct himself. Tanaka will have to locate his fastball in similar locations to where he was during the first two months of the season.

Locating his fastball on the corners of the strike zone is exactly how Tanaka can be most successful with it. Tanaka just isn’t able to blow anyone away with his fastball sitting around 92 and 91 mph, which means he has to rely on his location to be effective with his fastball.

The Yankees would love if Tanaka could recapture his 2014 form where he recorded a 2.77 ERA and a 9.3 SO/9. But, they would certainly be happy if Tanaka could record similar results to his performance during the first two months of the season, when he recorded a 3.20 ERA, 1.185 WHIP, 3.80 FIP, .247 OPP AVG, 22.6% strikeout rate and a 1.16 HR/9.