There is a difference between, 'passive' and, 'defensive.'
(@)tpr: '1 e3 is fine.' ~ Correct. 1. e3 takes good and bad things from 1. b3 and 1. Nf3.
A good thing: With 1. e3 instead of 1. b3, White keeps Qb3 possible, as well as the option of playing the Hedgehog's sister setup---1. e3 d5 2. Nf3 Nf6 3. c4 e6 4. cxd5 exd5 5. Be2 Bf5 6. Qb3 Qc8 7. d3 c6 8. Bd2 Nbd7 9. Bc3 Bd6 10. Nbd2.
A good thing: By delaying Nf3, White keeps f4 as a possibility.
A bad thing: 1. e3 is less flexible than 1. Nf3, and it does not allow a quick Bb2 to take the diagonal before Black gets a chance to.
'Nimzovich played it to win the 1929 Carlsbad Tournament.' ~ A good player winning with a strategy does not mean that the strategy is good (or fine); it just means that they won with it. You could win a tournament with the Grob if you got lucky with your pairings, your opponents are a lot weaker, or you just played better than them.
Singular tournaments are different from consistent results that take decades to form.
There is a difference between, 'passive' and, 'defensive.'
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(@)tpr: '1 e3 is fine.' ~ Correct. 1. e3 takes good and bad things from 1. b3 and 1. Nf3.
A good thing: With 1. e3 instead of 1. b3, White keeps Qb3 possible, as well as the option of playing the Hedgehog's sister setup---1. e3 d5 2. Nf3 Nf6 3. c4 e6 4. cxd5 exd5 5. Be2 Bf5 6. Qb3 Qc8 7. d3 c6 8. Bd2 Nbd7 9. Bc3 Bd6 10. Nbd2.
A good thing: By delaying Nf3, White keeps f4 as a possibility.
A bad thing: 1. e3 is less flexible than 1. Nf3, and it does not allow a quick Bb2 to take the diagonal before Black gets a chance to.
'Nimzovich played it to win the 1929 Carlsbad Tournament.' ~ A good player winning with a strategy does not mean that the strategy is good (or fine); it just means that they won with it. You could win a tournament with the Grob if you got lucky with your pairings, your opponents are a lot weaker, or you just played better than them.
Singular tournaments are different from consistent results that take decades to form.