Before CIS-2013, I thought Alex was just one of the top players, capable of roughly the same things as the others, but more focused, assertive, and goal-oriented, which is why he achieved such results.
But after watching his mirror matches, I realized that the difference between him and the other top players lies in his knowledge and understanding of the game. By giving up 2-3K gold for a color at the start, he managed to maintain the pace or even pull ahead from the very beginning, developing as well as, or even better than, his opponent by the end of the first week, and noticeably surpassing him in power, hero development, and explored territory by the second week. Every time, he planned a red rush on day 131 and bought the color specifically for it, but in reality, he didn't need to red rush; his army was stronger even without it.
Also, in my opinion, =Stinger=, GoD, Gomunguls, and HellLighT deserve recognition for obvious reasons that have already been mentioned many times.
P.S. Regarding the "battle" to determine the strongest, it's meaningless, in my opinion. This is a summary of the year 2013, and it's being done by the viewers. The players have already done what was required of them in 2013.