My suggestions: 50mm seems fine to me if you're close to the scene; don't shoot at 1.4 unless you have to, stop it down a bit, things will be sharper and you'll hit focus more easily; shoot in manual mode M and don't be afraid to underexpose for quite a bit, K30 can handle it in PP if you shoot RAW; shoot RAW, did I mention that before ? start with ISO 800 and 1/60 and see how it goes, then boost up the iso first up to 3200 (as Matt said) and if it's still not enough, then slow down the shutter speed. But I would use 1/60 and boost ISO up before changing the shutter speed. Don't be afraid if you see the exposure meter underexposing for 1-2 stops, just eye the photo on the camera screen and see how it looks. Try to get a few test shots before the action starts. Hope that helps! and post some pictures afterwards