Earlier this year, Bill Petti mentioned in his CLIFFORD work the single largest driver in a player’s wOBA collapse from one year to the next was Z-Contact%. Players that saw their Z-Contact% decline by at least 1.4% had a 1.68 times the odds of seeing their wOBA collapse that season than those that did not experience such a decline.
As with any correlation, nothing is a guarantee. Just because a player improves or declines with any one statistic does not guarantee that the results will behave in lockstep. The five players who saw their Z-Contact% improve the most in 2013 were Gerardo Parra, Everth Cabrera, Brandon Moss, Carlos Santana, and David Murphy. Parra, Cabrera, and Santana saw their wOBA improve by 1, 38, and 20 points respectively while Moss and Murphy’s dropped 33 and 80 points.
It was equally volatile on the other end of the scale. Raul Ibanez‘s Z-Contact% dropped 5.3%, yet his wOBA improved by 19 points. Chris Young‘s Z-Contact% dropped 6.2% from 2012 to 2013 as his wOBA dropped 36 points. Marlon Byrd’s 6.7% decrease was the third-largest decrease in Z-Contact% in the sample size, yet his wOBA improved an amazing 148 points last season. The two largest declines in Z-Contact% from 2012 to 2013 had one thing in common – a last name.
B.J. and Justin Upton had the two largest declines, but not in the order one would assume. B.J.’s Z-Contact% fell 6.8% from 79% to 72.2% last season while his wOBA fell 71 points from .323 to .252. Justin had the worst decline of all full-time players last season as his Z-Contact% score fell from 87% to 77.5%, but his wOBA actually improved by 16 points from .341 to .357.
In the short time it took to assemble the Brothers Upton in Atlanta, there were many pieces written on how the two would feed off each other as they achieved a life-long dream of playing together in the major leagues. In one particular piece by ESPN’s Jayson Stark, an anonymous scout offered this insight:
“That’s where the risk comes in,” said one scout with a background in coaching. “To me, it’s a maturity thing. Both these guys should be at a place in their lives where they understand what’s going on. They’ve had their travails elsewhere. And now they’ve got a chance to support each other. …
“This can be a really good thing if they’re able to feed off each other in a positive way. But if one of them is struggling or having problems with a coach or manager, then you could have two guys who aren’t happy with what’s going on instead of one.”
Justin’s 2013 was very top heavy in that he exploded out of the gate with a .458 wOBA in the month of April. 12 of the 30 fly balls he hit that month became home runs and he amassed an amazing 69 total bases during the month. From May 1st through the end of the season, the younger Upton’s strikeout rate improved while his walk rate slightly declined, but his wOBA was .332 and he hit just 15 home runs over the final five months.
His issues with Z-Contact% arose from problems with fastballs, something Jeff Zimmerman first pointed out in late June. What Zimmerman highlighted in June did not improve throughout the season. From 2011 to 2012, Justin Upton feasted on fastballs within the strike zone as he had a .402 wOBA and a Z-Contact% of 85.7%. Last season, his wOBA against fastballs within the strike zone fell to .324 and his Z-Contact% fell to 71.9%. Only three full-time players – Chris Carter, Mike Napoli, and Mark Reynolds – had lower Z-Contact% on fastballs last season. His wOBA against fastballs in the zone was in the lowest 25th percentile in the league and only Carter and Napoli had a higher percentage of strikeouts against fastballs.
Despite his struggles with hard stuff, Justin held his own against secondary pitches as his overall numbers were in line with his previous efforts. The same cannot be said about his older brother.
While Justin had the highest tw0-year difference in Z-Contact%, B.J. had the highest three-year difference. In 2011, the elder Upton brother had a 83.3% score, which fell to 79.0% in his final season in Tampa Bay, and down to 72.2% this past season with Atlanta. Fastballs in the strike zone previously were not an issue for Upton after he fully recovered from his serious shoulder injury in 2008. From 2011-2012, B.J. had a .349 wOBA on fastballs in the strike zone and had a Z-Contact% of 78.3%. Last season, his wOBA on those same pitches fell to .259 and his Z-Contact% dropped to five full percentage points to 73.3%.
Upton was known for his frequent tinkering of his swing in Tampa Bay, but it still surprising to read these types of quotes from late May as co-hitting coaches Scott Fletcher and Greg Walker talked about what ailed Upton:
“It’s an easy fix; it won’t take long,” said Upton, who is working with hitting coach Greg Walker and assistant Scott Fletcher to eliminate the excessive “load” portion of his complex swing, the part where he leans back before coming forward.
The flaw has caused him to be “chronically late” on fastballs all season, Walker said. The pitch arrives before he’s straightened his posture, and Upton ends up leaning back, swinging upward and usually beneath the ball.
As bad as Upton’s season was against fastballs, it was much worse against soft stuff. Being “chronically late” on fastballs will often lead to batters cheating on fastballs to catch up with them, leaving them susceptible to secondary pitches. From 2011-2012, Upton’s wOBA against soft stuff was in the bottom half of the league while his Z-Contact% was in the lower 25th percentile. Last season, Upton’s wOBA on those pitches was .185 and his Z-Contact% was 63.9%. He was the second-worst full-time player in both areas, finishing behind Dan Uggla in both cases.
Changeups were particularly problematic for Upton. From 2009-2012, Upton had a .307 wOBA against changeups in the strike zone and a 76.4% Z-Contact%. Last season, that wOBA plummeted to .132 and his Z-Contact% fell to 67.3%. Breaking balls were no picnic in the park either as Upton’s wOBA and Z-Contact% against those pitchers are in a three-year decline. His wOBA has fallen from .365 in 2011 to .203 this past season while his Z-Contact% has worsened from 22.9% to 34.7%.
Where the Upton’s go from here is the question. Justin struggled with fastballs in the zone last season, but still found success against other pitches. B.J. found extremely little success as he struggled across the board and performance on pitches in the strike zone are in a three-year decline. It is damn near impossible to correct what ails a batter in the middle of a major league season, so B.J. has the offseason to work with the Atlanta coaching staff to eliminate the flaws in his swing.
Despite the swing and miss in his game, he is a disciplined hitter who has a strong feel for the strike zone as his O-Swing% is in the top-third of the league over the past three seasons. The Braves were able to marginalize Uggla’s playing time down the stretch but they don’t have the same luxury with B.J. Upton. They need him to make the necessary adjustments to his swing to end this three-year decline in his in-zone production. Otherwise, the final four years of his contract will be a rather unpleasant reminder on the dangers of the free agency market.