Best By Test (part seven)

WHY does 1...e5 do so badly as a reply to 1.e4, both percentage-wise and in rating performance?
We saw in part two of this series that 1...e5 scores just 44%, which is below every other move, apart from 1...b6, that occurs at least 0.1 per cent of the time.
Its rating performance in those games is -28, well behind 1...e6, 1...d5, 1...c5 and 1...c6.
All statistics are based on 238,275 games played last year that appear in ChessBase's 2020 Mega database.
In the popularity table below I have excluded moves occurring less than 0.1% of the time.

Table 22: Popularity Of White Moves After 1.e4 e5
Move.......Number Of Times Played
2.Nf3.....................26,326
2.Bc4.......................1,192
2.Nc3..........................975
2.f4.............................519
2.d4............................405
2.d3..............................71
2.c4..............................63

The move 2.Nf3 is overwhelmingly most popular, occurring almost 90% of the time.

Table 23: White Second Moves By Percentage Score (ties broken by frequency of appearance)
Move.......................Score
2.d4..........................58%
2.Nf3........................56%
2.f4...........................56%
2.Bc4........................55%
2.Nc3........................55%
2.c4...........................37%
2.d3...........................32%

Table 23 is very tight at the top, with just three percentage points covering the most-successful five moves, the only surprise, perhaps, being 2.d4 coming out on top.

Table 24: White Second Moves By Rating Performance (tie broken by frequency of appearance)
Move..................Rating Performance
2.d4............................+39
2.Nf3..........................+32
2.f4.............................+3
2.Bc4..........................=
2.Nc3.........................-12
2.c4............................-12
2.d3............................-72

The move 2.d4 confirms its success, although White's traditional path of 2.Nf3 also scores very well.
The performance of the latter is probably of most interest to blacks who answer 1.e4 with 1...e5 as 2.Nf3 is played almost 90% of the time.
In the table below I have excluded moves occurring less than 0.1% of the time.

Table 25: Popularity Of Black Moves After 1.e4 e5 2.Nf3
Move..................Number Of Times Played
2...Nc6.............................22,580
2...Nf6...............................2,726
2...d6....................................896
2...d5......................................79
2...f5.......................................66
2...Qe7...................................44
2...Bc5....................................31

No major surprises here, unless you count that of 2...Bc5 passing the 0.1% threshold.

Table 26: Black Second Moves By Percentage Score (tie broken by frequency of appearance)
Move...............................Score
2...Nc6.............................45%
2...Qe7.............................45%
2...f5.................................43%
2...Nf6..............................40%
2...d6................................38%
2...d5................................33%
2...Bc5..............................21%

The success of 2...Qe7 is certainly surprising, but is from a small sample size.

Table 27: Black Second Moves By Rating Performance
Move.......................Rating Performance
2...Bc5..............................+19
2...Nf6...............................-14
2...d5.................................-24
2...Qe7..............................-25
2...Nc6..............................-31
2...f5..................................-47
2...d6.................................-49

I certainly did not expect this, but it should very much be borne in mind that 2...Bc5's success is based on just 31 games.
Many of those games featured low-rated and unrated players, which can be seen in that only five games saw the reply that is clearly the best, ie 3.Nxe5.