EAST BOSTON – In the illustrious history of the Massachusetts Handicap at Suffolk Downs, there have been 12 winners who were odds-on favorites. Barring an upset of epic proportions, No. 13 will happen Saturday.Commentator, coming off an eye-popping win in the Grade 1 Whitney Handicap at Saratoga, is the 3-5 morning line favorite in a field of seven for the 66th running of the MassCap. A seven-year-old gelding who has come back from two major injuries, Commentator appears to have plenty of margin for error Saturday.”I would say he feels the best and looks the best and works the best he ever has in his entire career,” said Commentator’s owner, Tracy Farmer. “He is at the top of his game right now. I never would have believed it.”The reason even Farmer may be surprised at the phenomenal year his horse is having – three wins and a second in four starts, including an unheard-of-for-a-seven-year-old 120 Beyer speed figure in the Whitney – is that the horse had layoffs of 10 and eight months due to a shin fracture he suffered shortly after winning the 2005 running of the Whitney.That seems like ancient history for a horse that has won 12 of 19 starts and earned $1.5 million for Farmer and Hall of Fame trainer Nick Zito. A sprinter for much of his career who ran a non-threatening seventh in last year’s Breeders’ Cup Sprint, Commentator has been able to carry his natural speed over a distance of ground, as indicated by his easy win in the 1 1/8th mile Whitney.”He understands what he is supposed to do,” Farmer said. “As long as he is in good health, when he takes control, it’s over.”Looking at the field for the MassCap, it’s hard to envision a scenario where Commentator, who drew the No. 2 post, will not take control from the outset. His main competition appears to be Dr. Pleasure, who finished third in last year’s MassCap and was 1-for-14 lifetime until winning a $75,000 allowance race by eight lengths at Saratoga Aug. 10.John Ward, a Kentucky Derby-winning trainer (Monarchos in 2001) who conditions Dr. Pleasure for owner John Oxley, said Dr. Pleasure had been suffering from a breathing problem earlier this year. The horse had an entrapped epiglottis, which prevented him from breathing properly. A procedure to correct it was done in early May and the horse responded with a 102 Beyer in the Saratoga win.”He seems to have found himself a new level to compete at,” Ward said. “We corrected the breathing problem, and now, with his training and his age (5), hopefully he can pick up six or seven lengths.”The $500,000 MassCap is worth $300,000 to the winner. Post time Saturday is 5:45 p.m. and the race will be televised live by TVG.