Questions yesterday about whether opposing hitters were more likely to walk in 2013 when Carlos Ruiz was catching for the Phils. That part’s easy — the answer is yes, they were. The harder part is how important that information is and I’m a lot less sure about that. In order to conclude anything, we’d need to look at more complete information about who was doing the pitching, the game situation and the quality of the hitters they were facing.

Still, the overall results were a little surprising to me. The Phillies used five catchers in 2013: Ruiz, Erik Kratz, Humberto Quintero, Cameron Rupp and Steven Lerud. Here’s the total number of plate appearances each caught and the team’s walk rate with them catching:

BF % of BF BB %
All PHI 6213 100 8.1
Ruiz 3251 52.3 9.0
Kratz 2060 33.2 7.5
Quintero 718 11.6 6.4
Rupp 116 1.9 6.0
Lerud 68 1.1 7.4
Not Ruiz 2962 47.7 7.2

So Ruiz caught 52.3% of the batters and during those plate appearances, Phillie opponents walked 9.0% of the time. The other four catchers caught 47.7% of the time and in those chances opponents walked in 7.2% of their plate appearances.

Here’s the breakdown for the three catchers other than Rupp and Lerud for the eight starting pitchers on the ’13 Phils that got at least eight starts.

Pitcher BF Ruiz Kratz Quintero
Hamels 905 61.8/5.9 26.4/5.9 11.8/2.8
Lee 876 55.0/4.1 39.2/3.2 5.8/2.0
Kendrick 800 38.8/4.2 55.1/6.8 6.1/8.2
Pettibone 437 52.6/10.0 21.3/7.5 26.1/7.0
Lannan 332 57.5/10.5 10.8/5.6 31.6/5.4
Cloyd 282 33.9/11.6 50.7/7.7 -
Halladay 282 50.0/16.3 15.2/11.6 34.8/8.2
Martin 190 66.8/15.7 24.7/10.6 -

So, looking, for example, at the top line, Ruiz caught 61.8% of the batters that Hamels pitched to in 2013 and those batters walked in 5.9% of their plate appearances. Quintero caught 11.8% of the batters Hamels faced in 2013 and those batters walked in 2.8% of their PA.

Cloyd and Martin both pitched to Lerud and Rupp. Those numbers aren’t included above.

Of the eight pitchers listed above, six of them pitched to all three of Ruiz, Kratz and Quintero. Of those six, five, everyone except for Kendrick, issued walks at the highest rate while pitching to Ruiz and the at the lowest rate when pitching to Quintero (for Hamels, the 5.9% to Ruiz is a little higher, 5.903, than his 5.9% to Kratz, which is 5.858).

The other of the six that pitched to all three was Kendrick. He walked batters at his lowest rate while pitching to Ruiz and at his highest while pitching to Quintero. It should be noted that Kendrick’s time pitching to Quintero was especially limited. Quintero was behind the plate for just 49 of the 800 batters that Kendrick faced (6.1%).

The other two pitchers on the list, Cloyd and Martin, didn’t pitch to Quintero, but each of them walked batters at a higher rate while pitching to Ruiz than they did to Kratz.

I think it’s hugely important to remember there are a lot of factors at play. For example, Roy Halladay and Ethan Martin each had very high walk rates for the season, regardless of who was catching them. Ruiz caught more than two-thirds of Martin’s innings and half of Halladay’s, which surely contributed to his walk rate being high relative to other catchers on the team. While the rate that each of those guys allowed walks was higher with Ruiz behind the plate, I still think it’s a leap to attribute much of anything to Ruiz without more complete information about the game situation and the quality of hitters the pitchers were facing.

If you look back at the last few years, it’s also not true to say that batters consistently walk more with Ruiz behind the plate than with someone else catching. It was in 2012, 7.1% for Ruiz and 6.2% for everyone else on the Phils, but in 2011 he was way under the walk rate with others catching (6.4% for Ruiz and 7.2% for everyone else). In both 2009 and 2010, the walk rate for hitters with Ruiz behind the plate was just about the same as the walk rate with anyone else behind the plate (6.8/6.9 in ’10 and 7.9/7.7 in ’09).