Trying to Make Sense of the Slumping Sox

Can Pedroia rebound?

As a brief warning, this post is centered around more advanced sabermetrics, so proceed with caution if you have arithmophobia. 

As most of us have noticed, the Red Sox have had a rocky start to the season and are currently in the middle of the pack in the AL and trying to keep up with the other teams in the AL East that are starting to heat up.

Here are a few stats to start off slow (Analysis will be further below):

ISO Down from .175 to .138 over the past year (Mar/April comparison). Middle of the pack at 15th right now, 6th at this time last year. Went from Above average to below. ISO is isolated power that translates into extra base hits:

ISO = ((2B) + (2*3B) + (3*HR)) / AB
ISO = Extra Bases / At-Bats 

Surprisingly, we struck out on 23.3% of our at bats last season which was 4th highest in the MLB for April. We are 15th right now with 21.3%.

One consistency is the plate discipline. We walk on 10.2% of our at bats, which is up from last year’s rate of 9.8%.

BABIP: We are currently down from .339 in 2013 to .300 in 2014. .300 is average, while .339 is quite high. Usually BABIP is because of luck, poor defense, or pitching adjustments. 

Now the UZR/150, which is used to more evenly judge and compare defensive efficiency (-.4 in 2013, -.7 in 2014) proves that defense has been slightly worse this season in the AL than last season. Also, we have to take into account the fact that the -.4 is calculated using the entire season while -.7 is just in the first month. This is important because the UZR/150 will settle as the batters tire down and the pitchers find their grooves. -.7 seems low and would be for an entire season, meaning a below average defensive season for the AL, but eventually hitter regression will cause a spike in that which would effect the BABIP of the Red Sox.

Other stats:

AVG down from .271 to .246 (.249 in 2014) (.251 - 2013)

OBP down from .347 to .333 (.317 in 2014) (.318 - 2013)

SLG down from .446 to .384 (.389 in 2014) (.401 - 2013)

wOBA down from .346 to .321 (.314 in 2014) (.316 - 2013)

and finally

wRC+ down from 115 to 98 (96 in 2014) (98 - 2013)

Takeaways:

We were overachieving in 2013. We knew this but our season thus far just proves it. We have regressed to the mean. Our AVG and SLG are below league average for this year, while OBP, wOBP, and wRC+ are slightly above the league average.

We were able to create runs extremely easily last year. wRC+ takes the 100 runs at league average and takes the additional number as the growth in percentage form. For example: the 115 wRC+ for the Sox last March/April means that they were 15% higher than the league average for run creation efficiency. Run Creation is vital to baseball because it takes into account each stat in a player’s stat line and weighs them to determine their efficiency compared to other players to provide a more fair evaluation.

The main contributor to our struggles:

No not the loss of Jacoby Ellsbury, but Dustin Pedroia. Dustin is down in almost every category:

Stat: 2013 2014

BB% 16.2% 7.5%

K% 13.7% 9.2%

BABIP .402 .300

AVG .337 .270

OBP .444 .325

SLG .398 .351

wOBA .377 .305

wRC+ 136 87

Analysis: 

3 keys stat differentials are walk percentage, BABIP, and wRC+. BB% is important because the drop shows lack of plate discipline which is intriguing because his K% is lower which means he is either swinging earlier in the count and struggling to scrap out at bats. If he isn’t walking or striking out at much, that must mean that he is settling for worse pitches which leads to his lower average and OBP. His lower BABIP is important because it means he was getting lucky last year. By comparison, Pedroia had a BABIP of .330 for March/April in 2008, which (as we all know) is when he won AL MVP. The incredible .402 BABIP was second only to Starling Marte (.418!) in the MLB (minimum 110 plate appearances). MLB average for BABIP was .298 for March/April. Pedroia’s BABIP of .300 was also his lowest since 2011. Finally, wRC+ is down from 136 to 87, which means that Pedroia has gone from being 36% more efficient at run creation than the rest of the league to start the season last year to now 13% less effective that the rest of the league this year. That steep of a drop is worrisome considering that it is the lowest wRC+ of his career for the first month of the season. I have faith that he can turn his poor start around because of his track record as one of the game's elite second basemen, but he'll need to do it soon if he hopes to keep the Sox in playoff contention.

Quick Hits: 

All of the following stats compare Pedroia to the other 10 AL second basemen with at least 100 plate appearances. Tied for last with Omar Infante with 0.2 BsR which measures effective base running. 2nd worse wRC+ (Marcus Semien has 78). 2nd lowest wOBA (Semien with .291). Lowest SLG (2nd lowest Semien with .367). 3rd lowest OBP (Kinsler 2nd, Semien worst). Interestingly, lowest ISO with .081 (Robinson Cano is 2nd with .082. Brian Dozier leads with .227!). Only Jose Altuve and Ian Kinsler walk at a lower percentage than Pedroia (7.1% and 4.8%, respectively). Dustin is the only 2nd baseman with at least 100 PA without a homerun (UPDATE: Dustin had his first homer, a grand slam Friday 5/3).