In the famous Abbott and Costello routine Who's On First?, the third baseman's name is I Don't Know. How perfect. Third base has long been a mystery for teams, a position that year after year goes unfilled; there are fewer third basemen (nine) in the Hall of Fame than any position.

The third-base position is not well stocked today mostly because it is a very difficult position to play, a position with a knock-it-down mentality that simply isn't much fun for most players.

In has been a rough last two weeks for third basemen, which is nothing new. One third baseman (Cal Ripken) announced his retirement, another (Scott Rolen) was sharply criticized by his manager even though he's on a 90-RBI pace and a third (Tony Batista) was on his way to the minor leagues before being claimed on waivers.

It has not been a good year for third basemen. Vinny Castilla was waived by the Devil Rays, Russ Davis was dumped by the Giants, Tony Fernandez was released by the Brewers and Ken Caminiti of the Rangers may be the next to go. Two others, Phil Nevin and Robin Ventura, may be traded.

The Cubs, Mets, Padres, Orioles, Yankees and Dodgers are among just the teams that have had extended periods of their history with a revolving third basemen. Today, what are the Giants doing at third? The White Sox? The Brewers? The Blue Jays? It is a hard position to fill because it is a complete-player position, one requiring production, great reflexes, good hands, a strong throwing arm and courage. It is a position of quickness, not speed, and it's hard to scout quickness. It's a stressful, anxious position, it takes a special kind of player to play it, yet teams have moved first basemen, catchers or outfielders there to get another bat in the lineup.

In 1978, near the end of spring training, Orioles manager Earl Weaver wanted Lee May in the lineup every day, so he moved Eddie Murray to third and Doug DeCinces to second. That lasted three games. Not just anyone can play third, but teams try that. Has any position had greater extremes than Brooks Robinson and Dave Kingman playing at the same time?

The Blue Jays thought they had their third baseman of the future in the 27-year-old Batista, who last year hit 41 homers, knocked in 114 runs and made the All-Star team. He was so bad this year -- .207, 13 homers, 66 strikeouts -- that the Jays felt he needed to go to the minor leagues to find his swing. But he was claimed on waivers by the Orioles, who had searched unsuccessfully for a young third baseman mainly because there was so little out there.

Toronto's loss of Batista shocked Blue Jay players -- he hit 80 home runs the last 2½ seasons -- but it's still a risky move by Baltimore, which picked up the final 3½ years of Batista's four-year, $16-million contract. Is he the answer? I don't know. He plays third base.

Rolen is 26, he has won two Gold Gloves and has averaged 26 homers and 92 RBI over the last four full seasons. After Chipper Jones and Troy Glaus, Rolen is probably the best third baseman in the game. But he has not done enough offensively according to his manager, Larry Bowa, who recently said his No. 4 hitter (Rolen) "is killing us." That really bothered Rolen. Now there's an outside chance that instead of building around him, the Phillies could trade him sometime before he becomes a free agent after the 2002 season. Rolen is a fabulous defensive player, which is not easy at that position.

Doug Rader, a former Gold Glove third baseman, once said that playing the position "is like recovering a fumble." Indeed. Unlike shortstop, there is no time for a third baseman to position himself because the ball gets to you so quickly. There are few situations more frightening for a fielder than playing third base with the infield in and a big right-handed hitter at the plate. Ron Santo, a former Gold Glove third baseman, was once knocked unconscious when hit in the stomach by a one-hopper by Frank Howard in spring training. Santo woke up in the hospital.

Ripken began his minor-league career as a third baseman, then moved to shortstop for 16 years, then went back to third. He says he got hit in the protective cup all the time at third base, but never got hit in the cup at shortstop (another Baltimore shortstop, Mark Belanger, played his entire career without wearing a cup; now that's trusting your hands).

Ripken's adjustment from shortstop to third was relatively easy, but that doesn't mean that because you can play shortstop, you can play third. Ask Rico Petrocelli and Jim Fregosi. Both were above average defensive shortstops who moved to third base late in their careers. Neither liked it, neither did particularly well because there was so little time to react and because they couldn't see the hitter's hands coming out of the hitting zone as they could at shortstop.

Many a third baseman (Mike Greenwell for one) moved to the outfield where it was much safer to play. And many a kid has decided against third base for the same reason.

"It's like catching," Brooks Robinson, the greatest defensive third baseman ever, once said. "Kids don't want to be a catcher. Kids don't want to play third base, either."

The plays a third baseman has to make are as varied as they are difficult. There is the nasty top spin grounder that explodes once it hits the ground. There is the dreaded in-between hop that often can only be played by letting it hit you in the chest. The bunt play requires great skill to get your feet together, barehand a ball that's bouncing and throw across the body. That's not the only hard throw. The one over the bag at deep third is a long one to first.

Ultimately, Cleveland's Jim Thome couldn't make that throw and was moved to first base. The A's moved Jason Giambi from third to first, also. Both Thome and Giambi are happier where they are now.

Will Rolen be happy again with the Phillies? Will Batista be Ripken's replacement in Baltimore? Will a new wave of third basemen, led by Padres' prospect Sean Burroughs, bring new life to the position?

I don't know.

It's tough to predict anything when it comes to third base.

Tim Kurkjian is a senior writer for ESPN The Magazine and a regular contributor to Baseball Tonight. E-mail tim.kurkjian@espnmag.com.