By BOB ROBERTS CLEVELAND, Ohio -- There is a saying at the Cleveland racetracks that I have lived by for decades. It goes, "Nobody has every jumped off the I-480 Bridge with tomorrow's Daily Racing Form in their pocket." Hope. We always cling to the notion that the losing will end and that a winning day is just around the stretch turn. It's the horseplayer's creed. Which is how I am approaching Saturday's $1.5 million Belmont Stakes. No, it's not an easy pick. You can't bet Always Dreaming, the Derby winner, or Cloud Computing, the Preakness winner, because neither of them is running. I'm backing Senior Investment, a 12-1 shot who closed with enthusiasm to finish third in the Preakness. He's bred for the Belmont's grueling 1 1/2 mile distance and is trained by a guy who is no rookie to the race known as the "Test of the Champion." Ken McPeek upset the 2002 Belmont with Sarava, who dashed the Triple Crown bid of War Emblem. A super longshot, he paid $142.50 for a $2 win bet.   Regarding what a puzzle this Belmont is, none of the 12 entrants has a victory at Belmont Park. Only one of them, Meantime, has even tried to triumph over the gigantic 1 1/2-mile oval. The lightly-raced colt (just four starts) finished second in the slop in the May 13 Peter Pan Stakes. The 149th Belmont Stakes is Saturday, with post time scheduled for after 6:37 p.m. (Eastern Time). It will be televised by NBC (Ch. 3 in Cleveland), with coverage beginning at 5 p.m. Here are sketches on the 12 hopefuls, listed by post position with early-line odds: 1. TWISTED TOM (20-1) - Unbeaten in last three starts after trainer Chad Brown added blinkers to his equipment. Let owner Gary Biszantz know if he bet on his horse. He's the founder of Cobra Golf. Free driver, or set of irons? Jockey Javier Castellano and Brown may team to win two-thirds of this year's Triple Crown. They scored the Preakness with Cloud Computing. 2. TAPWRIT (6-1) - Tampa Bay Derby winner didn't have best of trips in Kentucky Derby, finishing sixth, beaten 10 1/4 lengths. He's from the barn of Todd Pletcher, who trains Derby winner Always Dreaming. Perhaps Brown and Pletcher have a side bet, say a grand to the winner of two of