Dozen Grid Strategy Roulette: Best Tips & Tricks for This System . You can effectively increase your bet coverage from 12 to 24 numbers and win the majority of. To cover them quickly, there are three different Dozen bets on the roulette table marked as: 1st 12, 2nd 12 and 3rd There's also 3 Column bets marked on the . Our $ roulette strategy is a very simple one and it can be a lot of fun to play with it. You can Bet $5 on 10 random numbers from the third twelve (3rd 12).