Columnist Jeff Haney: Analyze carefully before betting baseball props

Wednesday, June 27, 2001 | 9:44 a.m.

Jeff Haney's sports betting column appears Wednesday. Reach him at 259-4041 or haney@lasvegassun.com.

At least four Nevada sports books have posted propositions related to Barry Bonds' pursuit of baseball's single-season home run record.

Bonds has hit 39 home runs for the Giants through 77 games and is chasing Mark McGwire's record of 70 homers, set in 1998.

Whether you think Bonds will fly past 70 or falter, read the fine print before wagering, as each sports book's proposition is worded differently.

The Imperial Palace has adjusted its number on how many homers the major league leader will hit. The IP recently raised the over/under figure to 67 home runs, up from 61 just a couple of weeks ago. Bettors must lay 115 either way.

Those who play the "over" can root for Arizona's Luis Gonzalez (32 homers) as well as Bonds, because the IP's prop specifies the major league leader rather than a particular player.

The Mandalay Bay sports book has posted the over/under on Bonds home runs at 70 1/2, with the "under" a fairly heavy favorite. Bettors playing the "under" must lay 280 to win 100, while the takeback on the "over" is plus 240.

At the Stardust, a proposition asks simply "Will Bonds break the home run record?" This is the same as posting an over/under of 70 1/2 on Bonds homers, because if he finishes with 70 the "No" cashes. "Yes" is plus 250 at the Stardust, while "No" is minus 330.

Bonds believers can find the best value, however, at the Reno-based Cal Neva sports book, which has posted an over/under of 69 1/2 home runs for the Giants slugger. The "over" is listed at plus 250 and the "under" at minus 300.

Note that if Bonds hits exactly 70, the "over" cashes at Cal Neva but loses at Mandalay Bay and the Stardust. Of course, it would also cash with room to spare at the IP, but at a much less attractive price.

Las Vegas-area gamblers can find the Cal Neva line at Club Fortune in Henderson.

An "under" bettor might make the following case: Bonds is on a pace to hit 82 home runs, but that assumes he will continue to hit a homer every 5.8 at-bats. That 17.2 percent home run rate (1/5.8) is probably too much to ask, considering McGwire's home run rate in 1998 was an all-time record of "only" 13.7 percent (1 homer every 7.3 at-bats).

Even if Bonds was to finish with 71 home runs, his rate would likely be around 14.9 percent (1/6.7), still significantly better than Big Mac's single-season mark. Hitting a home run every 6.7 at-bats over the course of a full season would have to be considered a more freakish occurrence than 71 homers, even if it lacks the storybook appeal and inherent drama of a cherished baseball record falling.

And all of those figures are based on a projected 478 at-bats -- which Bonds might not even reach due to wild cards such as injuries or opponents pitching around him in the heat of a pennant race. It's nearly impossible to conclude that he'll finish with many more than 478 at-bats.

Then again, that's why you have to lay a premium of minus 280 -- or more -- on the "under."

One asks "Will the Mariners break the AL record for wins in a season?" To do so, Seattle would have to win 115 games, most likely finishing at 115-47.

Bettors have been playing the "No," currently a minus 550 favorite. The takeback on "Yes" is plus 375.

After 75 games, the Mariners are 56-19, a .747 winning percentage. If they continue to win at that clip, they would finish around 121-41.

In order to reach 115 wins, Seattle would have to play .678 ball -- 59 wins, 28 losses -- from today through the end of the regular season.

Some hardcore baseball fans swear by a method developed by an old play-by-play man named Pythagoras and popularized in recent years by the Baseball Prospectus website. It seeks to estimate a team's expected winning percentage by using this formula: (runs scored squared) divided by (runs scored squared plus runs allowed squared).

Run the Mariners' numbers, and you'll find they "should be" about 50-25 instead of 56-19.

Tellingly, that "luck differential" (or whatever you want to call it) of six games is the largest in the major leagues this season. The Mariners are playing over their heads.

If Pythagoras is right -- and he's usually in the ballpark -- Seattle will finish around 108-54 (.667) rather than 115-47 (.702).

As recently as this past weekend, the "No" side on the Mariners was available at minus 300 at the Stardust. That offer was snapped up by wise guys and others who figured their mutual funds certainly weren't going to return 33 percent between now and the beginning of October.

By comparison, online sports book Intertops.com, based in Antigua, has the over/under on the Mariners at 109 1/2 wins, minus 110 each way.

The final baseball prop on the board at the Stardust asks, "Will Curt Schilling win 20 games?" The "Yes" side is a minus 160 favorite, with "No" listed at plus 140.

Schilling brings an 11-2 record into today's start for the Diamondbacks against the Astros. Barring injury, he figures to get another 18 or so starts the rest of the way.