Cubs Monthly Recap: June 2014

EDITOR'S NOTE: Due to work commitments for Naveen, he is replacing his weekly recaps with a monthly recap, which should afford him more attention to detail. See more from him at the end of this post.

The Cubs went 15-13 in June -- the first winning season of the month. At the end of June, the Cubs were fourteen and a half games back of the division-leading Brewers.

Runs Scored: 98 | Runs Scored per Game: 3.50 | Runs Allowed: 101 | Runs Allowed per Game: 3.61

Competition Adjusted Runs Scored: 0.86 | Competition Adjusted Runs Allowed: 0.89

The Cubs' staff pitched very well in June -- allowing 11% fewer runs than the average staff would have allowed against the competition the Cubs faced. This hasn't just been a June trend, over the course of the season:

1. Cubs pitchers have surrendered the 10th fewest number of runs in the majors (344) and fewer than four playoff teams, (Angels, Orioles, Brewers, Tigers)
2. Cubs starters are second in the majors in WAR (9.2), and the overall staff is third in WAR (11.1)
3. Cubs pitchers has posted the fourth-best FIP (3.39) in the majors

The Three Most Important Plays

6/17 Bot 7, men at first and second with one out, 4-3 Cubs: Garrett Jones homers off Brian Schlitter to give the Marlins a 6-4 lead, resulting in a -.491 WPA. The Cubs had a 59.2% chance of winning the game prior to his at bat, and a 10.1% chance of winning the game after his at bat.

6/16 Top 6, men at second and third two outs, 3-1 Marlins: Starlin Castro homers off Tom Koehler to give the Cubs a 4-3 lead, resulting in a .440 WPA. The Cubs had a 21.3% chance of winning the game prior to his at bat, and a 65.3% chance of winning the game after his at bat.

6/16 Top 13, man on first with two outs, 4-4 Tie: Travis Wood doubles off Jacob Turner to give the Cubs a 5-4 lead, resulting in a .417 WPA. The Cubs had a 43.9% chance of winning the game prior to his at bat, and an 85.6% chance of winning the game after his at bat.

Most Valuable Cub

Jake Arrieta: Arrieta was brilliant in June. He took a perfect game into the seventh inning of a game against the Reds and then came four outs shy of a no-hitter against the Red Sox at Fenway.

Arrieta posted a 0.92 ERA / 1.46 FIP / 2.07 xFIP line in June, which was good for the second best ERA, third best FIP, and fourth best xFIP in the majors. Furthermore, he posted the fourth best K-BB% (his 33.3% strikeout rate and 4.2% walk rate, led to a 29.2% strikeout/walk rate differential) in the majors. Arrieta was in the conversation with Felix Hernandez and Clayton Kershaw for June's best pitcher.

Let's take a step back and see how he got there. The results are at least partially a result of Arrieta's new approach. Arrieta is:

1. using his cutter much more frequently (nearly 30% of pitches thrown versus 14% the year before)
2. throwing strikes with his cutter (his ball rate on the cutter is below 30%)
3. generating swinging strikes with his cutter (13.8% swinging strike rate this year versus 11.5% the year before)

While we should always be wary of small sample sizes -- as fantastic as Arrieta's six starts in June were, they spanned 39⅓ innings -- research has shown that strikeout, walk, and ground ball rates stabilize at levels that Arrieta has already surpassed this season. Thus, his career-best strikeout (28.3%), walk (6.8%), and ground ball (49.7%) rates are likely here to stay.

Least Valuable Cub

Travis Wood: In 200 innings last year, Wood posted a 2.8 WAR season, the best of his young career. Entering his age 27 season, fans could have expected 2013 to be the start of a number of above-average seasons for Wood. Unfortunately, Wood has taken a step back this year. After posting a 13.5% walk rate in June, Wood's walking nearly 10% of batters faced this season, and it's his command that seems to be the root of hist struggles this year.

If we look at PITCHf/x data, we can isolate the pitches Wood is having the most trouble commanding. Last year, Wood threw 68.2% of his cutters for strikes; this year that figures stands at 61.8%. Batters also seem to be having more success against his cutter this year -- while hitters posted a .275 wOBA against the cutter last season, they're recording a .340 wOBA this season. Furthermore, Wood's slider isn't nearly as effective as it was last season -- hitters are posting a .362 wOBA against the slider this season versus a .231 wOBA last season and aren't whiffing nearly as frequently against the slider as they were last season (9.6% versus 13.5%). Wood's ability to make adjustments to his cutter and slider will play a large role in dictating his rest-of-season performance.

Up and Comers

I've switched from writing weekly recaps to monthly recaps for the following reasons:

1. Work continues to keep me busy, and often prohibits me from being able to post according to a weekly schedule
2. It's difficult to read too much into the data on a weekly basis as trends (that determine the most and least valuable players) are much more meaningful on a monthly basis
3. Writing monthly recaps will allow me to put some time towards interesting one-off pieces (observations on player performance, deep-dive reports on newly acquired players, etc.)