In Puzzle 6, you have a substantial lead. Because of your lead, you have two goals: outrun a potential bingo and reduce the probability of such a bingo from occurring. While INERTIAE scores well and has a high equity, it allows your opponent to bingo frequently. Likewise, any row 1 play will score well and let your opponent bingo, albeit for less points and less often than bingos after INERTIAE. Meanwhile, OPINE scores a few less points but makes bingos extremely improbable. It also creates a potential scoring spot so you can outrun potential bingos on future turns.