Ok lets follow some moves:

1.e4 e5 2.Nf3 Nc6 3.Bb5 d6 4.d4 (0-0!?) Bd7 5.0-0 Nf6 6.Nc3 Be7 7.Re1



For the time I want to omit lines where White plays Bc6 without beeing forced - I am not sure that giving up the bishop pair for some structural benefit is such a good idea.
Now Black has to give up the centre (7...0-0 may lead to the famous Tarrasch trap losing an exchange) with 7...ed4

After 8.Nd4 we reach an important point - Black can either go for further simplification with 8...Nd4 - this leads to a first critical position:



I think Black is very solid here, White may have some pressure but it will not be enough to get further concessions from Black and win the game - a slightly better position which will lead to a probable draw.



Black may also continue his development with 8...0-0 which leads to a second critical position:



Here I would suggest 9.Nf5!? netting the bishop pair which may give White at least some theoretical advantage.


I think Black is close to equalizing in the first critical position and may have some problems in the second critical position. But White cant avoid Black going for the first critical position other than taking on c6 before.

My conclusion at the moment:
Old Steinitz - no advantage for White

I hope someone is of a completely different opinion! - Perhaps above mentioned approach with 0-0-0 is the only correct idea to fight for an advantage.

I think some older books thought that White should get a clear advantage against the Steinitz with the approach involving Bxc6, Qd3 and 0-0-0 as played in a game Spielmann-Maroczy, but I believe += has been the consensus for some time now -- I think in a line with Black playing ...ed and ...g6 and White then (after Bxc6 bc) seeking to deprive Black of his bishop pair by means of Qd2 and Bh6 (so it seems to me without actually looking it up ...).