What was the difference between the world champion Giants of 2010, and the ragtag bunch that was outscored by opponents and limped home with 86 wins in 2011? The long answer: a less productive offense, a lack of decent fifth-starter options and Brian Wilson’s season-long struggles with health and consistency. The short answer: Buster Posey. But Posey, the talented, 24-year-old catcher, is back from a devastating broken leg, and once again that should make all the difference.

The Diamondbacks seemed to come out of nowhere in 2011, Kirk Gibson’s first full year as manager, improving by a staggering 29 wins over the year before and winning the NL West. In reality, they merely arrived a year early. And now that they’re here, loaded with young pitching (and with more, like Tyler Skaggs and Trevor Bauer, on its way), they’re not going away anytime soon.

Hidden amid all the drama with their ownership is the fact the Dodgers are a sleeping giant. Already in possession of arguably the best player (Matt Kemp) and best pitcher (Clayton Kershaw) in the league, they have precious few long-term salary commitments, and with the new Stan Kasten/Magic Johnson regime in place, they will be a team to watch this summer as the trade deadline approaches.

After ending 2011 as one of the most disappointing teams in the majors, the youthful Rockies – in defiance of recent industry trends — spent the winter getting older. They added 30-somethings such as Jeremy Guthrie, Michael Cuddyer, Marco Scutaro and Ramon Hernandez – and took the strategy to absurd heights by signing 49-year-old lefty Jamie Moyer. It’s doubtful the ploy will work, but at least Troy Tulowitzki doesn’t have to handle the leadership role all alone.

After a last-place finish in 2011, the Padres shocked baseball by trading their biggest asset – right-hander Mat Latos – in a four-for-one deal with Cincinnati. It’s difficult to sell a fan base on what feels like a perpetual rebuild (just ask Billy Beane), but it was clearly the right thing to do here, and the Padres might have something interesting by 2013.