Zack Wheeler’s big-league debut on Tuesday night went well. He held the Braves scoreless over six innings, allowing four hits, striking out seven batters, and showing impressive stuff. The only cause for complaint was that he walked five.

The walks weren’t a surprise. On Tuesday’s episode of Effectively Wild, I predicted that Wheeler would walk over four batters per nine innings in the majors in 2013—which wasn’t really going out on a limb, since Wheeler had already walked four batters per nine in the PCL this season. Before his first pitch, the Braves broadcast listed “fastball command” as one of Wheeler’s “keys to success” (though in his case it turned out to be more of a recommendation for success than a requirement). We knew that Wheeler was capable of missing bats, but we also knew that he was prone to missing the strike zone.

But early in Wheeler’s first start, the righty’s command looked even shakier than usual. Wheeler walked leadoff man Andrelton Simmons, and six of his first seven pitches were balls. After the seventh pitch, David Wright made a visit to the mound to calm Wheeler down; Daniel Murphy, Anthony Recker, and pitching coach Danny Warthen would make trips of their own later in the inning. Wheeler walked the fourth batter, Freddie Freeman, on this pitch,

which prompted a Braves broadcaster to say, “He’s got his adrenaline flowing, of course, so he’s trying to overthrow a little bit, and the ball is really flying up high.” On the Mets broadcast, Gary Cohen expressed similar sentiments, noting that Wheeler was having trouble settling down.

We’re used to hearing that pitchers who are making their major-league debuts tend to be amped-up and unable to find the strike zone, at least early on. So I was curious about what the stats would say about pitchers’ control in their debut starts. Here are the numbers for 446 rookie pitchers since 2001 whose first big-league appearance was a start. The “All Rookie Season Starts” line excludes any subsequent relief appearances.





All Rookie Season Starts




First Start




First Inning of First Start




The stats seem to suggest that rookie starters do have slightly worse strikeout-to-walk ratios in their debut starts than they do in the rest of their rookie seasons. And they have even worse strikeout-to-walk ratios in the first inning of their first starts (though that might have more to do with the fact that they’re guaranteed to face the top of the order in the first).* It’s not a huge effect, but it’s in the direction we would have expected. Wheeler wasn’t alone.

*Over this span, Marlins starter Graham Taylor walked the highest number of batters in the first inning of his first start—four, against the Phillies in April of 2009. He made only two more starts. Ben Kozlowski (2002) and David Purcey (2008) totaled the most walks in their first starts, with eight and seven free passes, respectively.

Thanks to Andrew Koo for research assistance.

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Home doubleheader for the 1st place Atlanta Braves. Opponents sporting two highly-touted young pitchers. Attendance: a bit over 21,000. Pathetic. The Braves organization has a great recent history of excellence, they deserve better support.
The Braves also had a young starter making his major league debut on Tuesday, Alex Wood. This time last year he was pitching for Georgia but he has flown through the Braves minor league system in the last year. Wood, like Wheeler, also appeared nervous and was walking way too many hitters.
If I were trying to look specifically at "first start jitters" I think I'd want to see simple BB%. You can actually be "effectively wild" and strike out plenty of guys while issuing walks, so K/BB might tend to water down that effect.

Care to share the simple BB rates from the same data set? Thanks.
Yes--I updated the post. The table now contains UBB% and K%.
Thanks. Just eyeballing it then, it does look like the "jitters" effect is driven mostly by increased walks - which conforms to hallowed intuition, at least.