The Red Sox aren't unique concerning bad starts. Plenty of teams have had abysmal starts but few have had as disappointing a start as the Boston Red Sox version 2011.1.
Why? I'll start with the obvious and speculate about the less so.
1) In every sport, you've got to play well to win. The Red Sox played terrible baseball in Texas, and didn't look much better in Cleveland. Whether you want to emphasize balance, run production, or run prevention there hasn't been much of any.
2) Starting pitching. Up until today, the Sox hadn't generated a single quality start. Quality starts (statistically) correlate with winning about two-thirds of the time, and are a meaningful statistic.
3) Anemic offense. After six games, the Sox have scored sixteen runs. That's not much of a sample size, but insufficient to win in any league. The old John McKay line applies, when asked about the execution of his team he replied, "I'm in favor of it."
4) Pressure. Are players starting to press individually and collectively because of a poor start? You have to wonder if the most important guy in the locker room is the sports psychologist, because the mental toughness factor hasn't shown positive thus far.
5. Preparation. Spring Training, frankly, felt like a joke. We heard how it doesn't matter, that when the bright lights come on and the big stage (i.e. major league ballparks) arrived, players would just turn it on. Don't say that you didn't hear it; everyone heard it. Now the Sox are in shell shock, and we haven't stopped watching, but they haven't started playing.
Sure, it's a marathon, not a sprint. But you have to leave the starting line.