Two Hopes for Noesi

The Mariners sent down RHP Hector Noesi to Tacoma today, and called up OF Carlos Peguero. The Mariners do not need a fifth starter for a while with the All Star Break coming up, and that's likely a factor in this decision, but the fact remains that Noesi got sent down. He is the owner of a 2-11 record with a 5.77 ERA this season - hardly unassailable numbers.

I hope that the Mariners sent down Noesi with two things to work on. He is far from a lost cause. I will start with a pretty picture (click on it for a bigger version). The explanation of the graph follows:

My Twitter feed has lit up on numerous occasions with fans angry that Noesi caught too much of the plate with an 0-2 pitch. He seemed to be singled out as a pitcher that does not know how to put batters away. The graph above supports the complainers. The vertical axis is "relative opponent wOBA," a stat I just made up. It is simply an opponents' wOBA in a particular situation (in this case a particular count) divided by the overall opponents' wOBA in all situations. Thus, a relative opponent wOBA above 1 signifies a count that Noesi is worse than his normal self in, and below 1 represents a count Noesi is better than his usual self in. Comment if you want a more thorough explanation/methodology for why I did this.

Last year, Hector Noesi exhibited trends that make intuitive sense. He was more effective when he was ahead in the count, and got steadily worse with more balls. The differences are large and noticeable.

Noesi is a different pitcher this year. His performance is noticeably worse when ahead in the count. However, what stands out even more to me is how little his performance changes in different counts. In fact, he has been at his best in 1-0 and 2-0 counts, which makes no intuitive sense.

Noesi relieved for the Yankees last season, and starters tend to pitch to contact more than relievers to be more economical with their pitches. Perhaps Noesi is too aggressive in the strike zone when ahead in the count. It would make some sense that batters perform roughly as well regardless of the count if Noesi is always trying to induce contact.

Hope #1: Hector Noesi works on expanding the strike zone with 2 strikes to generate more swings and misses or weaker contact.

I do not think that Noesi's approach is his biggest problem though. His pitch selection is different this season. He throws his curve ball half as often as last year, and his change-up about one and a half times more often. Noesi, as a right-hander, is likely more comfortable throwing curves against right-handers, and change-ups against left-handers. I decided to look at Noesi's splits to see if he is facing more left-handers this season.

55% of batters Noesi has faced this season are left-handed, up from 47% last season. The difference should not be too surprising. Managers can stack line-ups based on the starting pitcher they face that night. Nobody does the same for middle relievers. Noesi pitched better against right-handed batters last season, and he has the same trend this season too. Part of his struggles are simply a result of facing more left-handed batters, which also likely plays a role in his pitch selection.

Hope #2: Hector Noesi refines his change-up and explores more effective ways to retire left-handed batters.

The good news is that Noesi can work on both my hopes for him in AAA. He can take some risks that are harder to take in the higher-stakes world of the Major League Baseball. Noesi looks to me like a young pitcher still figuring out how to get through an MLB lineup three or four times, particularly one loaded with lefties. Noesi had success coming through the minors, and a solid 2011 campaign in the Yankees bullpen. He has work to do, but work that his past suggests he can accomplish.