I'm not the world's biggest Edinson Volquez fan. He's inconsistent, his walks rate are far too high, and he gives up quite a few homers for someone who induces as many groundballs as he does. He has, however, left the hitter-friendly Great American Ballpark for the more expansive and extremely pro-pitcher Petco Park.
He's made two starts totaling 12 innings in this early season, and both of them at Petco. The result? He's struck out 15 batters (11.3 per nine) and walked seven, but because of the punch outs, that's a 2.1 K/BB. Volquez's last (and only) K/BB over two in a season came in 2008 with the Reds.
Now, this isn't me saying that his K/BB is there forever, and that it's time to rush out to grab him. It takes much longer for stats to stabilize -- K/BB takes about 500 batters faced, and Volquez has seen 50 this year. It takes a little longer than that for walk rate alone to stabilize, but you can be sure that, with Volquez involved, the answer you're looking for there is going to be high. The real key for him is strikeout rate. That takes a lot less in terms of batters faced to start to be legitimate, but he still needs another 100 batters faced or so before we can say with any kind of knowledge where he might be.
Volquez still has to pitch in non-Petco environments, and it's unlikely he'll be that good all year in his new home park, too. But he's someone to watch for -- as frustrating as he is, there's a lot of talent there. And if he succeeds, you won't see him bumped from the rotation in favor of one of San Diego's many starting pitching prospects.
In a mixed league, given he will have half of his starts outside the friendly confines of Petco, Volquez might be too big of a risk. But if you've been wondering whether you should use him in your NL-only, given his past explosions, home games is a good start if you're looking for a boost to your stats.