user3207: In Indian chess, the pawn doesn't move two squares, however in the western chess, pawn can move two squares. Now, since the pawn can't move 2 in the Indian style, the fianchetto is a natural square to develop your bishops.
So for a player like Sultan Khan playing against other chess players from West, what kind of an Elo disadvantage would that put him? How does one estimate such a number?
Suppose one puts a constraint like this in Stockfish and lets it play against another Stockfish and observe how it does in a million games - would that be an acceptable way to estimate disadvantage?

user30545: Revised stockfish to skip searching double pawn push. Each engine is using 2 threads at TC 1m+1s. It got 4 draws in 20 games.
Test 1
sf_no_pawnpush4 is not aware that its opponent can play a double step pawn push and sf_normal is not aware that its opponent can only play a single step pawn push.
Score of sf_no_pawnpush4 vs sf_normal: 0 - 16 - 4 [0.100]
...      sf_no_pawnpush4 playing White: 0 - 7 - 3  [0.150] 10
...      sf_no_pawnpush4 playing Black: 0 - 9 - 1  [0.050] 10
...      White vs Black: 9 - 7 - 4  [0.550] 20
Elo difference: -381.7 +/- 252.4, LOS: 0.0 %, DrawRatio: 20.0 %
20 of 20 games finished.

Sample games:
https://lichess.org/UVMYm3Tf#6
https://lichess.org/sBp98pXn#84
Test 2
Each engine is aware of its opponent's capabilities.
Score of sf_no_pawnpush4_aware vs sf_normal_aware: 0 - 19 - 1 [0.025]
...      sf_no_pawnpush4_aware playing White: 0 - 10 - 0  [0.000] 10
...      sf_no_pawnpush4_aware playing Black: 0 - 9 - 1  [0.050] 10
...      White vs Black: 9 - 10 - 1  [0.475] 20
Elo difference: -636.4 +/- nan, LOS: 0.0 %, DrawRatio: 5.0 %
20 of 20 games finished.

Sample games:
https://lichess.org/l86RNFcn
https://lichess.org/A67hMP3i

3207: <p>In Indian chess, the pawn doesn't move two squares, however in the western chess, pawn can move two squares. Now, since the pawn can't move 2 in the Indian style, the fianchetto is a natural square to develop your bishops.</p>
<p>So for a player like Sultan Khan playing against other chess players from West, what kind of an Elo disadvantage would that put him? How does one estimate such a number?</p>
<p>Suppose one puts a constraint like this in Stockfish and lets it play against another Stockfish and observe how it does in a million games - would that be an acceptable way to estimate disadvantage?</p>
 30545: <p>Revised stockfish to skip searching double pawn push. Each engine is using 2 threads at TC 1m+1s. It got 4 draws in 20 games.</p>
<h3>Test 1</h3>
<p><code>sf_no_pawnpush4</code> is not aware that its opponent can play a double step pawn push and <code>sf_normal</code> is not aware that its opponent can only play a single step pawn push.</p>
<pre><code>Score of sf_no_pawnpush4 vs sf_normal: 0 - 16 - 4 [0.100]
...      sf_no_pawnpush4 playing White: 0 - 7 - 3  [0.150] 10
...      sf_no_pawnpush4 playing Black: 0 - 9 - 1  [0.050] 10
...      White vs Black: 9 - 7 - 4  [0.550] 20
Elo difference: -381.7 +/- 252.4, LOS: 0.0 %, DrawRatio: 20.0 %
20 of 20 games finished.
</code></pre>
<p>Sample games:<br />
<a href="https://lichess.org/UVMYm3Tf#6" rel="nofollow noreferrer">https://lichess.org/UVMYm3Tf#6</a><br />
<a href="https://lichess.org/sBp98pXn#84" rel="nofollow noreferrer">https://lichess.org/sBp98pXn#84</a></p>
<h3>Test 2</h3>
<p>Each engine is aware of its opponent's capabilities.</p>
<pre><code>Score of sf_no_pawnpush4_aware vs sf_normal_aware: 0 - 19 - 1 [0.025]
...      sf_no_pawnpush4_aware playing White: 0 - 10 - 0  [0.000] 10
...      sf_no_pawnpush4_aware playing Black: 0 - 9 - 1  [0.050] 10
...      White vs Black: 9 - 10 - 1  [0.475] 20
Elo difference: -636.4 +/- nan, LOS: 0.0 %, DrawRatio: 5.0 %
20 of 20 games finished.
</code></pre>
<p>Sample games:<br />
<a href="https://lichess.org/l86RNFcn" rel="nofollow noreferrer">https://lichess.org/l86RNFcn</a><br />
<a href="https://lichess.org/A67hMP3i" rel="nofollow noreferrer">https://lichess.org/A67hMP3i</a></p>
