First, the Tigers are a potential trade partner for a catcher. They have four catchers with major league experience:
Alex Avila, age 25, with a career fWAR of 8.6.
Bryan Holaday, age 24, with a career fWAR of 0.0 in 12 at bats.
Gerald Laird, age 32, with a career fWAR of 6.6.
Victor Martinez, age 34, with a career fWAR of 29.1. Martinez hurt his knee in 2011 and had microfracture surgery in Januaryof 2012. He did not play this year.
The Tigers also have something of a payroll crunch, so a deal is not a total pipe dream.
Second, you can see that teams do not have to be perfect to make it to the post-season. The Giants are a very average offensive team (wRC+ of 99) and the Tigers are an above average offensive team (wRC+ of 105). The Bucs show up at 90, well below average. However, the Tigers are a fairly brutal defensive team. Their UZR is -28.1, leading only the Astros, Rockies, and Indians. At 8.6 the Giants are slightly worse than the Pirates (10.8).
Of course the Tigers can really, really pitch. What's interesting is that, once again, the Giants aren't all that special. Pick your metric. ERA? Good, fifth in the NL at 3.68, compared to the Bucs' 3.91. FIP? Good, at 3.78, seventh in the NL compared to the Bucs' 3.94. You like xFIP? Again good, ninth in the NL at 3.95 compared to the Bucs' 3.97. You like fWAR? It's 14.7, compared to the Bucs' 12.2. You do not have to pitch like the Tigers, field like the Braves, and hit like the Yankees or Angels to play in late October.
Third, it's the World Series!! Why wouldn't you watch?