It is amazing to me that even today. People believe Alpha Zero is the best chess engine of all time, and is still the strongest chess engine today. A Chess.com poll also confirms this belief by the chess community that Alpha Zero is the best chess engine of all time.
This shows you what a good job DeepMind did in the press releases. By cherry picking stats to promote to the public. And by only counting wins and losses of a 1000 game match and ignoring the draws.
But even under the best results against Stockfish 8 playing without a book, or proper time controls, and sub optimal hash table settings. Alpha Zero was still less then 50 Elo better then Stockfish 8. With Stockfish 8 playing on weaker hardware.
When you look at the match played in 2018 were Stockfish 8 was able to play with a book against Alpha Zero. And this is important as Stockfish 8 is not a neural network engine. But a hand coded chess engine. So Stockfish 8 does not have the advantage of knowing how to play the openings like a neural network chess engine.
Alpha Zero results got even worse playing Stockfish 8. Here are the results and Elo of that 100 game match played with books, but still with Stockfish 8 playing Alpha Zero with sub optimal settings on weaker hardware.
Computer Match 2018
1 AlphaZero +31 +17/=75/-8 54.50% 54.5/100
2 Stockfish 8 -31 +8/=75/-17 45.50% 45.5/100
Now Alpha Zero in this more proper match with books playing Stockfish 8 lost 8 games to Stockfish 8. Not the widely reported and only remembered 6 losses in a 1000 games.
Now Alpha Zero beat Stockfish 8 by only 31 Elo points.
And this is confirmed by my centipawn analysis error rate of both Alpha Zero, and Stockfish 8.
Alpha Zero scored a error rate of .03 CP
Stockfish 8 scored a slightly worse error rate of .05 CP
So the conclusion that Alpha Zero is the best chess engine of all time is clearly wrong. And by the Elo Statistics Alpha Zero is weaker then today's Dragon, Stockfish, Lc0, Berserk 10, Koivisto 9, Revenge 3, RubiChess, Ethereal 13.75, Slowchess Blitz, Seer, Rebel 16, RofChade, Minic, Igel, Uralochka, Arasen, and Ginkgo Vienna.