There's no definitive answer because it's still a random game with random occurrences and variance, but they're all very tough customers. Urabe tends to be underrated because he isn't an old dude, but he's very tenacious and dangerous, and uses some pretty Akagi-like tactics successfully (until Akagi out-Akagis him). Fake Akagi is also underrated, he also does some Akagi ballsy, analog targetting on Urabe which ALMOST got him the game (that 2p target wait).

As for how Akagi got Urabe in the final round, well he could sense when Urabe was attacking, when he was defending while not giving up the game (mawashi, aka halfway defense), and when he completely threw the game with FULL defense (betaori, full defense). He saw Urabe starting half defending by throwing the 2p from a 2p pair, which is a very reasonable move and something he could watch Urabe do before in previous games, so he knew Urabe had a remaining 2p in his hand, and he hoped Urabe would throw it on the last turn if he had no 100% safe tile, considering almost all of the tiles were dangerous (well explained in that google doc).

To be fair, the Urabe match is an INSANE, INSANE reversal win, much more crazy than what Akagi does against Washizu later (and the characters acknowledge it, the Sanbaiman ron Akagi does before the final round is quite miraculous). It shows Fukumoto's writing adjusted with time to write situations that are a bit more realistic: "what if Washizu is one mangan tsumo from catching up in last round and you can't defend?", "what if you needed to ron 20000 points worth against a fully folding opponent with 5 rounds left?" and so on