It depends how you quantify luck. Halladay had two no-hitters last season. Statistically, the odds of that happening are absurdly low and I think most people would agree that a lot of getting a no-hitter is luck. That doesn't mean that on those particular days, the odds weren't much higher--that Halladay wasn't bringing "no-hit stuff." In the same way, it's totally possible that from start to start, or even for longer stretches, pitchers like Lannan or Ubaldo are able to pitch to weak contact. The only reason people are skeptical of it is because so few pitchers have been able to maintain those kind of results consistently, and pretty much all of them save Lannan have had pretty solid explanations for how they were doing it. Given the choice between "this guy is perhaps the only guy we studied who is able to do this" and "there are a lot of pitchers out there, so a few of them have to get lucky," stats people tend to assume the null hypothesis and take option B, while fans take option A. The more data we have, the closer we'll be towards determining who was right.