Boggs' struggles need no introduction after last night's fiasco, and most VEB members are aware of the volatility of reliever performances, so let's take a look at the underlying indicators of his performance and see if there's anything that explains his current awfulness. All this is from his Fangraphs page. I used the Pitch FX numbers when it comes to pitches thrown, etc.
1. His velocity on his fastball/sinker has dropped over 1 mph from last year to this year. 1.3 on his sinker (which he throws ~60% of the time starting last year), and 2 mph on the four seamer (just ~10%). His slider velocity (his 2nd pitch) is up slightly to 89 from 87.8, narrowing the gap between his fastballs and breaking ball a bit.
2. He is actually pitching in the zone as much as he did last year (a little bit less than 1 pct point higher actually; 47.7% vs. 47%), which is odd since his BB% has jumped from 7.1% to 18.3% (career mark is 10.3%).
3. Batters are actually making just a smidge LESS contact against Boggs than last year, down to 79.9% contact on swings from 81.2% in 2012.
4. The trouble seems to be coming from the fact that this year a significant amount of contact is coming on pitches in the zone:
- Batters are swinging at 26.6% of pitches outside the zone, compared to 29.8% last year.
- Likewise, swinging at pitches in the zone is up to 67.4% from 64%.
- Overall, they are swinging at about the same pace: 45.9% vs. 46%.
- Contact on pitches OUTSIDE the zone is WAY down: 54.8% from 68.5%.
- Contact on pitches IN the zone is up somewhat: 90.7% from 87.8%.
I'm not sure how that all fits together, exactly, or how much of it is useful given the sample sizes involved.
It does seem like hitters are making much better contact against Boggs; his line drive pct. is up to 26.9% from 19.2%. Batters are swinging at fewer balls out of the zone, and at more in the zone. This might explain why he seems to be getting hit so hard, but it also provides a clue to why his BB% is up so much when he is throwing the same percent of pitches in the zone. Batters are both laying off the pitches outside the zone, and making less (presumably bad or below average) contact on those pitches, leading to fewer easy outs and higher pitch counts & more walks.
It's hard to know what's what in a world of small sample sizes, but here is a rundown of possible culprits:
- A drop in velocity for his fastballs/sinkers, as well as a reduced velocity gap between his sinker and slider.
- A mechanical flaw, or pitch tipping that allows hitters to see the ball better and make stronger contact.
- A similar flaw that has lead to hitters being more selective at the plate, allowing them to draw more walks and swing at better pitches to hit.
Footnote: I would appreciate it if someone would contribute to this and see if his movement on pitches has changed from last year to this year, or provided a link for doing so.