all animu/manga is deus ex machina, since the writer doesn't actually rely on probability to determine who's going to win. but there is good, and bad storytelling.
akagi is an example of good storytelling since it's coherently explained in the context of the series how akagi manages to pull off what he does. hell, 90% of akagi you only hear the narrator explain wtf is happening. also, keep in mind that akagi, as well as his opponent don't only rely on luck and their skills to read people's behaviour, but also on cheating.
death note does a good job as well, at least in the beginning.
code geass is a marvellous example of bad writing. strategy and tactics are displayed incoherently and instead of focussing on actual execution, the viewer is only presented results ("HAHA, I ALREADY PLANTED BOMBS WHERE YOU POSITIONED ALL OF YOUR TROOPS"), the series doesn't explain in context why specific things were done, ("why? well... the main character is a strategic genius, duh.").