I'm pretty sure every fan is mad when a rookie starting pitcher throws a good game against his or her favorite team. After all, the reasoning goes, these guys should crack under the pressure and take their lumps during their first go-round in the league. Even worse is when some teams seem to struggle habitually against young starters. To see if that's true, I decided to take a look at recent performances by young starters (note: I use young as a general term: Tom Shearn debuted at 30, which is not young in baseball terms, but I think he's the exception, not the rule) against each team.
I looked at starts by pitchers in the first ten games of their career against each team since 2000. I don't think there's anything special about a pitcher's tenth career game as opposed to his eleventh career game, but it's a round number and generally only a short way into the pitcher's career. I looked at the final result of the game (win or loss), as well as the average runs scored off the young pitchers against the average runs scored per game by each team from 2000-2007. The results are below.
|San Francisco Giants||40||29||.580||6.29||4.78||1.51|
|New York Mets||48||38||.558||5.69||4.50||1.19|
|Tampa Bay Rays||37||46||.446||5.56||4.43||1.13|
|Kansas City Royals||42||47||.472||5.79||4.68||1.11|
|Boston Red Sox||42||27||.609||6.41||5.35||1.06|
|Los Angeles Angels||48||36||.571||5.93||4.88||1.05|
|Toronto Blue Jays||55||39||.585||5.63||4.94||0.70|
|Chicago White Sox||61||35||.635||5.76||5.08||0.67|
|Los Angeles Dodgers||46||38||.548||4.94||4.51||0.43|
|St. Louis Cardinals||55||30||.647||5.44||5.04||0.40|
|New York Yankees||45||29||.608||5.79||5.51||0.28|
|San Diego Padres||38||38||.500||4.44||4.48||-0.04|
Apparent basic arithmetic errors in the final column (see the last row) can be explained by rounding.
I sorted the list by the final column because I thought it was more telling than winning percentage in relevant games. The teams that lost more than half their games against young pitchers are also the teams that lost more than half their games anyway. It doesn't seem to make much sense to penalize or favor a certain team for the quality of their pitching staff. Rather, it makes sense to evaluate a team's performance against young pitchers based on the offense they generate against them. As I said above, I used run average based on the sums of innings pitched and runs allowed by the young pitchers and compared it to the average runs scored against all pitchers by each team in the past eight seasons. I thought it was interesting that the Padres and Diamondbacks actually scored less against young pitchers and that the teams near the top of the list actually aren't that great.
This doesn't tell you much in the grand scheme of things, but now you have something to point to when complaining about how your team's hitters always get beaten by young starters.