Getting on base is an important skill, so you want to use OBP to determine if the player in question is a good offensive performer. However, OBP can only take you so far and it should only be used in the context of other statistics because OBP weights every time you reach base equally, whether you hit a home run or an infield single. If used in conjunction with slugging percentage or isolated slugging percentage, OBP is a very useful tool. In general, something like wOBA or wRC+ will tell a more accurate story, but if you’re looking for something extremely simple OBP is a much better bet than batting average.
OBP has become synonymous with the book “Moneyball” because at in the early 2000s, teams weren’t properly valuing players with high OBPs and the Oakland A’s could swipe talented players for cheap because they were one of the few teams paying attention to walk rate. These days, every team has come to accept how vitally important OBP is to their success, and that particular “market inefficiency” has been closed.
The last notable disadvantage of OBP is that it is not park or league adjusted. It is easier for players to post a higher OBP in parks such as Fenway Park or Coors Field than the Oakland Coliseum or Petco Park. Likewise, OBP has fluctuated throughout time. Carl Yastrzemski led the American League with an OBP of .395 in 1965. However, in 2001, Jason Giambi put up the highest mark at .477. There are ways to adjust numbers for park and league context, but we'll save that topic for a later date.