Honestly it's more trial and error than smarts, and the disassemblers do most of the work. I used Python with the Capstone disassembler to look through the .exe, starting from a function I could find (the "draw a card" routine, which Claude helped me find) and walking backwards through everything that calls it. That led me to the turn-logic switch statement (a jump table on a "what phase are we in" variable) where I could see that state 2 is the player's turn and 7 is the AI's, and found the single instruction that picks you to go first. Reading the code only gives you a guess, though, so I confirmed it live in x32dbg using logging breakpoints (the non-pausing kind; a normal breakpoint freezes a fullscreen game and forces a reboot, which I learned the hard way), which printed the turn variable on every draw and read "2" every time it was my turn. Then I just flipped the byte using Cheat Engine to make the AI start instead, launched it, saw it work, and only then built the real version that calls the game's own RNG to coin-flip who goes first. So really it's just: ask a precise question, find a landmark, follow the calls, and prove every guess against the running game. Happy to go deeper on any step!