It may have garnered the biggest rating of any cable-TV broadcast in two years, but the BCS championship game on ESPN Monday night failed to draw the record audience that many writers had predicted. The reason was conspicuous in the score: Alabama 42/Notre Dame 14. Tellingly, ratings for the first half of The Game had seemed to suggest that a record would indeed be set, but with Alabama leading 28-0 at halftime, many casual viewers switched channels and never returned. Nielsen said that the game produced a 15.7 preliminary household rating, up 14 percent from the 13.8 overnight rating for last year's contest but down by about the same percentage from 2011. The record for a title game was set in 2006 with a 21.7 for the contest between the Texas Longhorns and the USC Trojans. Complete ratings with actual viewer numbers are expected to be released later today (Tuesday).