The Giants declined to offer arbitration to free agent catcher Bengie Molina, allowing his future team to sign him without fear of additional penalty in the form of draft pick compensation to San Francisco. It also seemingly clears the way for the unholy union between Molina and the Mets, not that something like draft pick compensation would've stood in the way between Omar Minaya and a lousy baseball decision (we weren't going to sign that draft pick anyway!).
Even though the Mets have already handed a guaranteed contract to Chris Coste and have seemingly signed Henry Blanco to back somebody up, I'd peg the odds at 50-50 that Molina winds up in Queens. How bad would that be? It depends on the contract, but probably pretty bad. Molina has been worth around two wins with his bat in each of the past five seasons, which is pretty solid, especally for someone who only plays 120-130 games a year. If that were the end of the story, you could make a reasonable case that a one-year deal worth $5 million with a second-year option might be a decent investment. Molina's bat probably wouldn't be worth much more than that, but there's no shame in merely getting your money's worth.
The problem, as you've probably already guessed, is that there's more to baseball than just hitting, and that's where the case for Molina falls apart. In addition to offensive contributions we also have to consider defense and baserunning.
Evaluating catcher defense is tricky business, but two recent efforts have made positive strides towards usefulness. This post by Matt Klaasen at Driveline Mechanics breaks down a catcher's credits and debits into "caught stealing runs", "wild pitch/passed ball runs", "throwing error runs", and "fielding error runs". By this method, Molina clocks in at -3.4 runs, or minus one-third of a win. Then we have this post by Chuck Brownson at Beyond The Boxscore, which also includes run totals for "baserunning" and "misses", but also incorporates "reputation", or the likelihood that a runner won't steal based on the catcher's rep. Molina charts at -7.06 runs above average.
Things don't get any better for Molina when he takes to the bases (something he managed to do on his own in just 28.5% of his plate appearances last year). Regularly considered one of the slowest runners in the league, Molina was worth -4.5 EqBRR in 2009. The Bill James Handbook has him down at -17 bases, which is probably about the same as his EqBRR in terms of runs (I'm not sure of the translation from bases to runs; obviously it depends somewhat on which 'base' we're talking about).
If we add up Molina's debits for defense and baserunning, plus factor in another year of age-related decline, we're pretty close to ten runs (or one win) to the bad. Now we've gone from a two-win player with the bat to a one-win player overall, which is hardly anything worth falling over yourself to acquire. For comparison, Omir Santos was worth between one-half of a win (StatCorner) and one win (FanGraphs) with his bat last year in just a half-season, and the defensive metrics rate him quite favorably (Klaasen had him at +2.4; Brownson at +14.5!), though his baserunning was as bad as Molina's (-3.0 EqBRR). If we say that his defense and baserunning 'offset' each other, we're still left with a near-one-win catcher making the league minimum, which makes it pretty tough to justify paying Molina dramatically more than that.
Someone is going to give Bengie Molina two guaranteed years at $6-8 million; I just hope it isn't the Mets.