Earlier in the week I explored why exactly does Edwin Jackson suck. Travis Wood has been equally bad this year. That has been a source of surprise and frustration for many. Travis Wood was the Cubs lone All-Star representative last year. This year coming out of the break Wood has an ERA pushing 5. But why does Travis Wood now suck?
The peripherals are something that I tend to look at first. Pitchers walk and strikeout rates are often more indicative of the way a pitcher is actually performing than just ERA. The theory goes that once a batter makes contact with a ball that things beyond the pitchers ability come into play in determining the outcome. That is why people better at math than I have come up with measures like xFIP which look almost solely at strikeout and walk rates to determine a pitcher's performance in areas that he can control I don't agree completely with home runs being out of the control of the pitcher, but looking at Travis Wood's xFIP for the past four seasons is interesting. Here is numbers starting in 2010 and moving to the present 4.61, 4.62, 4.50, 4.60.
That presents a couple of interesting scenarios. One is the luck narrative. Travis Wood could have been insanely lucky last year and this year is have a ton of regression plus a little bad luck. There are some other numbers to support that theory with his BABIP at a very low .248 last year and a high .311 right now. LD% is something that correlates strongly with BABIP and his LD% is actually lower this year than last year (22.3% to 20.5%). Another thing that suppresses BABIP is IFFB%. Infield flies tend to turn into out more than other types of contact and thus lower a pitcher's BABIP. Again his numbers are better this year than last year in that area moving from 14.2% to 15.0%. So the luck theory holds some water, and that we should except some positive regression from Travis Wood the rest of the year. But he is not the guy that went to the All-Star game last year moving forward.
The other possibility is that Travis Wood's skills have changed and that there is a legitimate reason for the difference in performance between the two years. There is evidence to point to this as well as his groundball rate has actually increased this season from 33% to 39%. He is also walking a lot more batters. The BB% is a career worst 9.7%. Combine that with the pedestrian K% of 18% and the picture for declining performance is pretty clear. One interesting note before we move on to pitchf/x data is the difference in K/9 compared to K%. Travis Wood is striking out a near career best 7.24 per 9 IP, and that illustrates one of the advantages of using K%. Wood is making more outs by strikeout than he did last year, but on a per batter rate he is right in line with his career numbers for strikeouts.
Travis Wood throws a lot of cutters. Travis Wood throws more cutters than any other left starter. His mix of cutter and four seam fastball is also pretty unique among left handed starters. The obvious first place to start is a decline in velocity on the cutter.
The cutter is indeed dropping in velocity, and is down nearly a full mph in average velocity from last year. That is certainly a possibility. Another interesting tidbit is that the changeup and slider have actually increased in velocity slightly as well. Sometimes the difference in velocity in more important than the actual velocity of individual pitches. This declining gap might be a legitimate cause of the decline we are seeing in Travis Wood this year.
Wood's pitch usage is also interesting given the sharp rise in sinker usage at the expense of the four seam fastball. His jump in groundball rate makes a bit more sense in this context now. However, the cutter usage remains extremely high though. Here is the type of contact that Travis Wood is giving up on his pitches this year.
The first chart shows that on a per swing basis Travis Wood is getting less whiffs on all of his pitches except the cutter. The line drive percentage on the cutter has remained mostly similar as has the amount of power against the cutter. The one thing that has changed is a fairly significant jump in batting average. That points us back to the luck narrative a bit more strongly.
The end result of this digging is that Travis Wood is probably experiencing a loss of skills and a loss of luck. His command has not been as good this year and his margin for error is very small given his overall stuff. The drop off in performance is made more dramatic by the positive luck that Travis Wood experienced last year. There is reason to be optimistic that a pitcher in his late 20s can make some minor corrections and perform better than he currently is, but the rush to add Travis Wood to the core of the future Cubs contender was most likely premature last year.