Over the last two seasons, no pitcher did a better job of preventing hits with runners in scoring position than Yovani Gallardo. What's interesting about this stat is that Yovanni's approach to hitters indicates this might be more than luck.
First, look at how Gallardo pitches to hitters with the bases empty.
(In these heat maps, pitch location is on the left, pitch movement on the right.)
The thing to note here is that Gallardo attacks the strike zone. He pitches to contact in the sense he doesn't walk batters in this situation only 8.8% of the time. He gets strikeouts about 25% of the time, and batters hit .244 in this situation. With no one on, Gallardo challenges hitters.
The pattern changes with men in scoring position:
Not here that Gallardo works more toward the edges, leaving a low frequency swath down the middle of the strike zone. In addition, he throws more pitches with downward movement. The upshot is he walks more, 15.1%, strikes out a tiny bit more, 26.2%, but because he works away from the middle of the plate, batters hit just .188 against him in this situation. He's willing to trade walks for fewer hits, since walks won't do as much damage in that particular situation.
Can this last? His BABIP allowed with runners in scoring position is an incredibly low .228. That should be unsustainable. Yovani does show batters something very different compared to pitching with the bases empty, and maybe that's enough to keep hitters off balance, leading to positive outcomes for the Brewers.