I posted some of this reply in a thread at Rotoworld, but I thought it would make for an interesting topic. I keep hearing that spring training stats are meaningless. I at least partially disagree.
IMO in general ST stats are NOT meaningless, but they need evaluation based on what you're looking at. Here is how I break it down.
1 Guy was good\great, but was injured\sucked last year. If he sucks in ST, ignore or move down on draft list.
2 Guy was good\great, but was injured\sucked last year. If he rakes in ST, look for value pick.
3 Top prospect. If he sucks in ST, ignore.
4 Top prospect. If he rakes in ST, look for value pick and astound your friends. Beware hype train driving value.
5 Mid level prospect. If he rakes in ST, ignore, but keep an eye out for a breakout. Maybe late pick in deep league. DON'T put this guy in your starting lineup.
6 Everyone else. Ignore.
So I'm mostly use ST to gauge someone's potential recovery from a down year, or to see if a top prospect may be ready for the next step.
An example would be Lester. This guy was a stud, but had a down year last year. Currently he's doing well in ST - 24ip 20 k 0.75 era 0.50 whip. Based just on last season I wouldn't be touching him until late. But looking at ST, is he possibly turning it around? His ADP is still around 11 so probably no value pick here, but that may not be a bad place to take him.
At the other end is obviously Halladay. He had a down year last year, and has had an ever worse ST. I'm worried and have moved him down the lists. Does he turn it around? IMO he does, because I believe in him and as a Phils Phan I have my Philly blinders on, but 7.2 ADP is way too rich for my blood. Do I miss out on a potential top 5 SP? Maybe but I don't take pitchers early. At 7.2 that may be my first pitcher and I don't want to gamble with what should be my #1.
I'd feel more confident of Lester than Halladay at this point.
Matt Harvey was more than solid in his debut last year. Now he's doing just great in ST. I'm not as worried about him as I would be if he was getting shelled, and I'm looking to grab him with confidence. Doesn't mean he'll work out, but those are always the chances you take.
So use ST stats for evaluation, mostly as guidance around recovery, and a bit less as a watch for breakouts.