After 1.c4 Nf6 2. Nc3 g6, thousands of games have been played with the following two moves of white: 3.g3 and 3.e4. It seems that the winning percentage suggested that 3.e4 is clearly better than 3.g3, though interestingly, more games are played after 3.g3 than 3.e4.

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1.c4 Nf6 2. Nc3 g6

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So my question is that, can one conclude that 3.e4 is better than 3.g3 based on the winning percentage?

Similarly, in a position where thousands of games have been played, if say after Move A white's winning percentage is significantly higher than after Move B (say by 5%) and at the same time, the winning percentage for black is significantly lower, is it sufficient to conclude that Move A is better than Move B?

  • The winning percentage is just one helpful indication. – Inertial Ignorance Sep 28 '19 at 23:42

The precise answer depends largely on the database, and the answer is still never yes.

If the database includes any players below 2500ish OR it includes blitz or rapid time controls, do NOT attempt to rely on these percentages. Inaccurate moves were likely played and possibly "moved to the top" of the possible moves.

You could possibly rely on percentages for main lines with high rated players and long games, but it's still a little risky.

I would recommend looking instead at established opening theory books/websites as well as Stockfish.


No, these winning percentages should be taken with a grain of salt, especially for as early as move 3. The percentages largely depend on the type of players that go for certain lines. For example, if more inexperienced players favour 3.e4 more often, more of the 3.e4 games will have an inexperienced player playing White.

The percentages are simply one of many indications of a move's strength. Generally you should pay more attention to the number of games a move has, since that tells you if it's the main line or not.

  • 1
    The number of games can also be misleading sometimes, e.g. if the previous main line (lots of games) of a variation gets refuted by a novelty (much smaller number of games; so no big impact on percentages yet as well). – Annatar Feb 25 '19 at 7:57
  • True but that tends to be very rare. – Inertial Ignorance Feb 25 '19 at 18:52

I use the opening percentages when I review my games - never before.

Sometimes I'll see that my opening scores "70%" for my opponent - not good for me, even if I did win. So why did I win?

After looking at why it scores so high for my opponent, I see he missed a good move.

But even then, the move has to be so good, it's forcing - as in, it's actually a trap. However, most of the time it only leaves my opponent with an advantage of 0.6 in his favor. I can live with that.


Where were your data taken from? What do you know about the population? If the stats were the last 10 years of GM Tournaments around the World, well that would be a good guideline for two things:

  • Avoid a potential harmful move, everyone knows how to counter.
  • Study for Novelties (moves that you are gonna be established in new theory of openings with ! or !? and will not give any disadvantage while they stabilize or create interesting positions.

What value do those data have if taken from online chess games though? Well since the ELO rating in that case has greater variance and the intentions, timeouts also vary, since it is not a tournament that you give your best, you just play a game on the internet, you should take those data with a huge grain of salt, as you were already told. The data do not determine anything in this case.

For instance, if 5% of the population are Masters, while the rest 95% varies significant lower, the data means nothing. On the other hand if 100% of the population are Masters, they knew what they were doing, so we can make more accurate assumptions.

If the data were for internet games, you get what they just tell. At average you should prefer a move from another on an ONLINE game.

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