Is there any broad-brushed strategy for either side that would gradually but decisively achieve victory?
Sounds like what you are really asking here is "Can black survive long enough, without giving back too much material, to take advantage of the extra material to win." That's because white's winning strategy would have to be to checkmate black quickly and that's not a gradual process and in any case, as you say, the engines evaluate the position as close to equal out to move 10.
If there were such a strategy for black it would be something like:
- Avoid checkmate
- Avoid giving back too much material
- Get the queens off
1 is achievable, 2 is achievable for a while but white can easily sidestep 3.
Although a rook for a pawn up, black is facing an immediate checkmate threat, Nd6#, plus Qe6 looks really nasty, plus the white squares around the black king are very weak.
The most obvious move, Qb6, protects against both the checkmate and Qe6 but is one of many second favourites of the engine. As some of the comments point out, Nb6 is the first choice of the silicon-based players.
This carbon-based player likes the look of Nc5 which also protects against both the mate and Qe6 and aims to return some material to get to a more comfortable, albeit more materially balanced position, with a sequence like 1...Nc5 2. cxd4 Qd7 3. Nxe7 Bxe7 4. dxc5. Then black can choose between Rd8 threatening mate (albeit easy for white to parry) and O-O.
It could go something like this:
[FEN "r2qkb1r/pp1nn1p1/7p/5N2/3p4/2P2N2/PP2QPPP/R1B3K1 b kq - 0 1"]
1...Nc5 2. cxd4 Qd7 3. Nxe7 Bxe7 4. dxc5 Rd8 (4...O-O 5. Qc4+ Kh8 6. Be3 Bf6) 5. Be3 O-O 6. Rc1
Of course the engines don't go for any of this cowardly stuff. They prefer, as black, to hang on to the extra material as long as possible, even at the expense of having to make a number of "only moves":
[FEN "r2qkb1r/pp1nn1p1/7p/5N2/3p4/2P2N2/PP2QPPP/R1B3K1 b kq - 0 1"]
1...Nb6 2. Bf4 d3 {only move} 3. Qe6 Nc8 {only move unless you want to allow white a draw by repetition} (3...Qd5 4. Nd6+ Kd8 5. Nf7+ Ke8 6.Nd6+) 4. Ne5 Qd5 {only move} 5. Nd6+ Qxd6 {only move} 6. Qf7+ Kd8 7. Rd1 Qf6 8. Rxd3+ Nd6 {only move} 9. Qxf6 gxf6 10. Nf7+ Kd7 11. Nxh8 Nec8
At the end of the day the computer has given back material, black is up a piece for two pawns, but in return white has allowed the exchange of queens. White's more active pieces means that the evaluation in black's favour is less than 0.5.
I think the outcome under perfect play is unlikely to be a draw. So who is most likely winning here?
I think the outcome in such a double-edged position with human play is unlikely to be a draw. More scope for mistakes means humans are more likely to make them and lose, but the computer suggests that with perfect play it is a draw.
