Sandy Koufax has long been a touchstone for those short but great careers -- for obvious reasons. Koufax is considered one of the greatest pitchers in baseball history, but he retired at 30 and stuffed almost all of his value into a glorious six-season period (1961-66). There's a temptation to say that anyone with a terrific but short career -- Ron Guidry, Bret Saberhagen, Wes Ferrell, Dave Stieb -- must, like Koufax, be a potential Hall of Famer.

This is especially true for Johan Santana because, as the argument goes, he was similarly dominant from 2002-10. I am actually bullish on Santana's Hall of Fame case. He was down to the final two for my last Hall of Fame vote. I will get into all that in just a minute.

But first I have to say this: I think the Koufax-Santana comparison is terrible and does absolutely no favors for Santana.

I've written about this some before, but here is the problem with Hall of Fame comparisons: We have a bad habit of only comparing the stuff that makes our own case look better. That's why the "If this guy is in, then this guy has to be in," reasoning is so often shallow and even ridiculous. The most famous example of this came from the "Committee to Elect Ken Keltner," who in their efforts to put in the former Cleveland third baseman, bragged that "he had a higher average than Eddie Mathews, more RBIs than Jackie Robinson and more hits than Ralph Kiner."

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You obviously see right through this absurdness. If not, well: I have countered that my hero Duane Kuiper has to go to the Hall of Fame because he had more stolen bases than Ted Williams, more triples than Johnny Bench and more home runs than Pedro Martinez. I mean, how do you not put Kuip in the Hall of Fame?

These are obviously extreme examples -- but the point remains. No two players are entirely alike no matter what their career statistics say. Comparisons are useful, of course. They are one of the fun parts of any Hall of Fame discussion. But they are a guide, nothing more. And the reason is they are biased. They punctuate the part of the argument you want to punctuate and ignore the part that you want ignored.

Keltner had 350 fewer home runs than Mathews. He led the league in home runs seven fewer times than Kiner (which is to say, he never led the league in homers or anything else except games played in 1939). He integrated one fewer league than Robinson. These are fairly easy points to miss, if you want to miss them.

The Santana vs. Koufax argument is a perfect example of this.

Let's say, for argument's sake, that Santana was, at his best, as good a pitcher as Koufax. It's a difficult argument to prove. They pitched in entirely different times and in entirely different ways.

Koufax in his four best seasons averaged 298 innings per season. He pitched when great starters were expected to finish games. In those four great years, he finished almost 60 percent of the games he started.

Santana in his four best seasons averaged 239 innings per season. He pitched in a time for closers, he was almost never allowed to finish games. In those four great years, he finished 6 percent of his the games he started.

Koufax pitched in an era when pitching reigned. Plus, he pitched on a ludicrously high mound in maybe the greatest pitchers ballpark since World War II. As such, his ERA for his five best seasons is an extraordinary 1.95.

Santana pitched in a good offensive time in a home ballpark that slightly leaned toward hitters. In his five best seasons, his ERA was almost a full run higher -- 2.82 -- but in context it was pretty close. (Koufax had a 167 ERA+; Santana a 157 ERA+).

And finally, Koufax pitched in a time when one team in each league made the playoffs. The National League had 10 teams; one got in, there were no consolation prizes. You had the best record in the league or you went home. Koufax played a major role -- the major role -- in leading his team to three World Series in four years.

Santana pitched in the Wild Card era, when four of the 14 teams in the American League made the postseason. Santana played a major role -- the major role -- in getting Minnesota into the postseason by winning the American League Central.

All this makes it awfully hard to know how Santana would have pitched in the 1960s, or Koufax in the 2000s. But we do have some very good statistics that allow us to compare each to their league and time -- as you can see in the tweets throughout this story -- and these do make the case that Santana at his best was similar to Koufax at his best.

You don't need advanced stats to make this case. Koufax won three Cy Youngs and an MVP in a four-year period. In Santana's heyday, he won two Cy Youngs and should absolutely have won in 2005. He did not win an MVP award but certainly had a case in 2006, when his teammate Justin Morneau won it.

Sounds pretty similar. So what's the problem? Why does comparing Koufax and Santana hurt Santana's case?

Well, all this ignores one kind of important thing: Koufax is a legend because of how he pitched in five World Series. This wasn't a sidenote to his story. This was at the heart of his story. If Koufax had the exact same career but his team never made the World Series, sure, he'd still be considered a terrific pitcher. We might still talk about his perfect game (in large part because of Vin Scully's incomparable call) and his 382 strikeouts in 1965 ahd how sad it was his career ended when it did.

But would he be Sandy Koufax, name in the brightest of lights, the guy who sparks goosebumps every time you see him at Dodger Stadium?

Of course not. It would be like talking about, say, Joe Montana's career without the Super Bowls.

Do we need to remind how good Koufax was in the World Series? In 1963, he pitched Game 1 against the Yankees, struck out 15 (he got Mickey Mantle twice) and won. He pitched on three days' rest, came back for Game 4, and threw another complete game, outdueled Whitey Ford and clinched the series.

• Santana elected to Twins Hall of Fame

That was nothing compared to 1965. He pitched Game 2 -- you will remember that was the year he did not pitch Game 1 because of Yom Kippur -- and was not at his best. He lasted only six innings; he gave up just two runs, but Minnesota's Jim Kaat was better. The Twins took a commanding 2-0 lead in the Series.

Koufax came back on three days' rest to pitch Game 5 -- he threw a shutout and struck out 10. The Dodgers were on the brink of taking out the Twins. But the Twins won Game 6. And so Koufax came back on two days' rest and threw another shutout with 10 more strikeouts, and the Dodgers won the Series again.

The next year, with Koufax's arm seemingly connected by nothing but a string, he lasted only six innings and gave up one earned run. Jim Palmer beat him. Koufax led the Dodgers to the World Series with amazing seasons, he started eight World Series games, several of them on short rest, finished with an 0.95 ERA, won two World Series MVPs and created a Yom Kippur legend that will be talked about every Yom Kippur forever.

We can talk all we want about Johan Santana's ERA+ and Wins Above Average. He was not Sandy Koufax. Nobody was. Koufax was a man of his own time, his own place. He achieved his own greatness.

Santana's Hall of Fame case must stand on its own. To me, that comes down to the basic question: How long does someone have to be truly great to merit entry into the Hall of Fame?

Santana's case is that from 2003-08, he was absolutely the best pitcher in baseball, and nobody was all that close.

Wins Above Average 2003-08

1. Johan Santana, 27.4

2. Brandon Webb, 23.3

3. Carlos Zambrano, 20.8

4. Roy Oswalt, 19.4

5. Roy Halladay, 19.2

For those six seasons, he was the best in everything. He had the most wins. He had the lowest ERA. He had the lowest ERA+, the lowest WHIP, the lowest batting average against, he was the best pitcher, absolutely and without question. If you are the best pitcher or player in baseball for six seasons, should you be in the Hall of Fame?

Yes. I think you should.

Well, I don't know if six years is the right number. Maybe it should be five. Maybe it should be eight. These things are worth arguing about. I know this: There will be four players elected this year, I think. I would not have traded Santana in his prime for any of them.

Despite this, Santana looks like he will fall off the ballot after just one year, and that's sad. If there is one part of the Koufax comparison I like, it is that Koufax reminds us all of how large a shadow a great player can cast in a short period of time. Santana was not Koufax. But he was the best of his time.

And for that he deserves more love than he's getting.