A Sabacc dealer at Canto Bight turned Imperial strategist, D8 knows how to manipulate the odds into his favor. He is excellent at hedging his bets, observing patterns, and - in certain cases - changing the outcome to a more favorable one. His capacity to "tell the odds" and occasionally cook the books earned the attention of Imperial officers who brought D8-D8 into Imperial service. D8-D8 now serves as a battle strategist for Imperial squadrons eliminating Rebellion expeditionary forces into core worlds. D8 is able to quickly assess battle scenarios, leading to many Imperial victories.
However, D8 is also a notorious liar. His ability to predict outcomes is nearly matched by his deceptive interference with Imperial intelligence, which has earned him quick promotions through empty leadership roles. Were these roles vacated due to higher-ups ineptitude or D8's planted "intelligence"? Hard to say.
Recently, D8-D8 calculations have begun to indicate a downward trend in probability for Imperial success since the destruction of the second Death Star. D8-D8 wants to fold and cash in before it's too late.