By Richard Rushfield, Los Angeles Times Staff Writer When the two Davids do battle Tuesday night, they will face off in the most evenly-matched contest since the last two-boy finals, Season Twos Ruben vs. Clay. The oddsmakers are split, the pundits are divided and for the first time in years anyone could win. But who will win
? We have broken the contest into its basic categories. Here is your guide on how to read the final showdown of Season Seven.