There was some debate about this in the Dunn thread(s), but I can't remember if anyone said what he claims, or whether that a walk can be equal to or better than a hit. In regards to the components of OBP, the reason to prefer a higher walk rate is consistency. Walk rate is one of the more predictable stats. The higher that is, the more likely a player has to have a consistently high OBP. Also, like you say, a high average that props up an OBP can be attributed to an abnormally high BABIP, making it less likely for a player to repeat that production. EDIT: Obviously there are players that defy the above statement by hitting .300 or better with a decent walk rate for a good portion of their careers, Pierre and Nomar prior to this year are good examples. Both are on the wrong side of 30 though, and with that means a drop in bat speed, and without the walk rate, a drop in production.