In the wake of Yadier Molina's five-year, $75 million contract extension with the Cardinals, several emailers wondered whether Carlos Ruiz will be in line for a big pay-day once his current contract expires. As valuable as Ruiz has been for the Phillies, the comparison isn't a fair one.

For starters, Ruiz will be 33 years old this season and he still has a $5 million option for 2013. So he won't be hitting free agency until he is entering his 35-year-old season. To put that in perspective, when Molina's new deal expires, he will be entering his 34-year-old season. The age difference alone -- Molina will be 29 this season -- is enough to render any comparison moot.

Those making the Molina/Ruiz comparison are probably looking at offensive numbers alone. Over the last three years, Molina has hit .287/.348/.397 (.745 OPS) with 26 home runs in 415 games, 1583 plate appearances. Ruiz has hit .281/.376/.417 (.793 OPS) with 23 home runs in 360 games, 1284 plate appearances.

While Ruiz's numbers are better, Molina has been more durable (55 more games, or more than a third of a season, over the last three years). More importantly, though, is his ability to limit opposing base-stealers, something the Phillies have experienced first hand on many occasions.

A catcher's ability to stop an opponent's running game is difficult to quantify. There are so many different variables outside of the catcher's arm strength. Players will tell you that they don't steal bases against a catcher, they steal them against the pitcher. If a pitcher is slow to the plate, even the strongest of throwers is going to have a difficult time getting the ball to second or third in time.

That being said, we can at least try to get a statistical perspective of Molina's impact. I figure the most intuitive way to do this is to look at how many runners reached base during his time behind the plate, and then look at how many of those runners ended up stealing a base. To do this, we add the number of hits allowed, number of walks allowed, number of hit by pitches, and the number who reached on error, then subtract the number of home runs (since a hitter who hits a home run will never have a chance to steal a base).

In 2011, the Cardinals allowed 1,499 base-runners and 46 stolen bases when Molina was behind the plate. The Phillies allowed 1,215 base-runners and 77 stolen bases when Ruiz behind the plate. In other words, Molina allowed a stolen base once every 32.59 base-runners. Ruiz allowed a stolen base once every 15.78 base-runners. The National League average was one steal for every 17.69 base-runners.

So when Ruiz was behind the plate, he was more than twice as likely to allow a stolen base than when Molina was behind the plate.

Again, Ruiz's pitchers might have been slower to the plate than Molina's. Ruiz might have had runners that were in better base-stealing situations than Molina. It's impossible to say definitively that Molina is twice as much of a deterrent as Ruiz.

But it doesn't take a seasoned scout to see the havoc that Molina's arm can wreak on an opponent. And when you combine that tool with the fact that he is four years younger than Ruiz, you'll find two players whose contract situations are incomparable.


Today's Phillies coverage from Clearwater. . .

Fan outrage over the Nationals' "Take Back the Park" campaign is simply playing into Washington's hands. I think that's a good thing. A new I-95 rival is just what we need to spice up the regular season.

Bob Brookover trolls the stat-heads (actually, he takes a look at the Phillies' use, or lack thereof, of advanced metrics)

Matt Gelb looks at the improvement in power on the Phillies' bench.

John Smallwood likes the new playoff format