Steinitz could do everything well, and Lasker beat Steinitz.  So what was Lasker doing?

We are used to seeing the many photos of Lasker taken when he was an old man, but we must notice that Lasker was a young man when he beat Steinitz in 1894.  So age may have had something to do with it.

But there are a couple of other things: 

1. He won five games in a row in the middle of the match, in part because he steered for positions that he thought Steinitz didn't handle so well -- queenless middlegames (where the Queens have been swapped and not much else).

2. And Lasker was a tough man to beat, very tough.  He put up endless resistance, not just stubbornly, but cleverly, making life awkward for his opponent.

To see what Lasker can teach us, let's look at a game from another great player, Botvinnik.

Black is a pawn down against the Bishop pair on move 20.  So... he gives up another pawn!  But does so getting a passed c-pawn.  

On move 20, White was a pawn up and clearly winning. On move 26, he was two pawns up... and things weren't so clear!

So that's what I mean by being awkward. Put your nuisance hat on, and imagine what moves your opponent would hate to see. Play moves that ask hard questions... and they might get one of them wrong.

[Event "How Good is Your Swindling?"]
[Site "How Good is Your Swindling?"]
[Date "1933.??.??"]
[Round "?"]
[White "Alatortsev, Vladimir"]
[Black "Botvinnik, Mikhail"]
[Result "0-1"]
[ECO "E52"]
[PlyCount "86"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3 b6 5. e3 Bb7 6. Bd3 O-O 7. O-O d5 8. cxd5
exd5 9. a3 Bd6 10. b4 Nbd7 11. Nb5 Be7 12. Ne5 a6 13. Nc3 c5 14. bxc5 bxc5 15.
Rb1 {[#]} Qc7 $4 16. Nxd7 Nxd7 17. Qb3 Rab8 18. Nxd5 Bxd5 19. Qxd5 Rxb1 20.
Bxb1 {[#]  How Good is Your Swindling?} c4 $1 {White has (1) an important
decision to make, which is taxing anyhow...} (20... cxd4 21. exd4 Nf6 22. Qf5
Rd8) (20... Bd6 21. h3) 21. Bxh7+ $2 (21. Qe4 $1 Nf6 22. Qc2 {with the advance
of the central Pawns. Black's position here is worse than if he had chosen 20..
.cxd4.}) 21... Kxh7 22. Qe4+ Kg8 23. Qxe7 {[#]  with two Pawns, but...} c3 {(2)
Black has counterplay.} 24. e4 (24. a4 c2 25. Ba3 Rb8 26. Rc1 Qc6 27. h3 Qxa4 {
which is comfortable for Black}) 24... c2 25. d5 $2 Rb8 26. g3 Qc8 {[#]  Not
over yet, but Black's practical decision has transformed his chances.} 27. Qg5
Qc4 28. f3 Rb3 29. Qd2 Rd3 30. Qe2 Ne5 31. Kg2 Rd1 32. Qxc4 Nxc4 33. d6 Kf8 (
33... Nxd6 34. Kf2 Nb5) 34. a4 Ke8 35. Kf2 Nd2 36. Re1 (36. Bxd2 Rxd2+ 37. Ke1
(37. Ke3 Rd1) 37... Rd1+ (37... c1=Q#) 38. Ke2 c1=Q) 36... Nxf3 37. Rf1 Nxh2
38. Re1 Nf3 39. Rf1 Nd2 40. Re1 Nb3 41. Ba3 c1=Q 42. Bxc1 Rxc1 43. Rxc1 Nxc1
0-1

This is a harder game to follow, but the story is easy to understand.

Again, on move 20, Black is two pawns up and clearly winning. But it gets less and less easy as the game goes on, and Lasker comes up with one idea after another, and Black never gets control of the position.

[Event "World Championship 05th"]
[Site "USA/CAN"]
[Date "1894.04.03"]
[Round "7"]
[White "Lasker, Emanuel"]
[Black "Steinitz, William"]
[Result "1-0"]
[ECO "C62"]
[PlyCount "91"]
[EventDate "1894.03.15"]
[EventType "match"]
[EventRounds "19"]
[EventCountry "USA"]
[Source "ChessBase"]
[SourceDate "1999.07.01"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 (3... f5) 4. d4 Bd7 5. Nc3 Nge7 6. Be3 Ng6 7. Qd2
Be7 8. O-O-O a6 9. Be2 exd4 10. Nxd4 Nxd4 11. Qxd4 Bf6 12. Qd2 Bc6 13. Nd5 O-O
14. g4 Re8 15. g5 Bxd5 16. Qxd5 (16. exd5 Rxe3 17. fxe3 Bxg5) 16... Re5 {[#]} (
16... c6) 17. Qd2 (17. Qxb7 Rb8 18. Qxa6 Rxg5 (18... Bxg5) 19. Bxg5 Bxb2+)
17... Bxg5 18. f4 Rxe4 19. fxg5 Qe7 20. Rdf1 Rxe3 {[#]  Black is two pawns
ahead, and 'clearly' winning.  Lasker tries hard to make it less clear...} 21.
Bc4 Nh8 (21... Rf8) 22. h4 {White's first idea is easy enough: ratlle the
King's cage.  There are three more ideas that Lasker plays that are far from
easy!} c6 23. g6 $1 {That's harder to spot!  Lasker offers to go three pawns
down, just to open the h-file.} d5 $2 {'Playing safe' but this is already a
mistake.} (23... hxg6 24. h5 g5 25. h6 g6 26. h7+) 24. gxh7+ $1 Kxh7 25. Bd3+
Kg8 26. h5 Re8 27. h6 g6 28. h7+ Kg7 {[#]  Second hard to spot idea:  White
wants to get things going on the King's-side, but Black has the big idea ...
Re1+ which might swap off pieces or worse, lead to White's King being driven
out and attacked.  So before going further on the King's-side, Lasker makes an
escape tunnel for the King.  That takes a lot of nerve, I think!} 29. Kb1 (29.
Qh2) 29... Qe5 30. a3 c5 {[#]  Third moment: ...c4 is coming, when it looks
like the Bishop will have to retreat.  But if White starts retreating, it's
all over...  So Lasker finds a way not to retreat the Bishop.} 31. Qf2 c4 32.
Qh4 $1 f6 {[#]} 33. Bf5 $1 {I think faced with this position, lots of players
would play Bf5, after all, giving up a whole piece for two pawns is useless
when you are two pawns behind!  The real skill was to see this possibility
coming a couple of moves ago. so that it's not a desperate move, but a very
smart one.} Kf7 (33... gxf5 34. Rhg1+ Kf7 {is like the game} (34... Kf8 35.
Rg8+ Ke7 36. Rfg1)) 34. Rhg1 gxf5 {The rest of the game is very tough for
Black, although the position may still offer level chances.  But tiredness, or
nerves, and maybe the clock, get the better of the old Champion.} 35. Qh5+ Ke7
36. Rg8 Kd6 37. Rxf5 Qe6 38. Rxe8 Qxe8 39. Rxf6+ Kc5 40. Qh6 Re7 41. Qh2 $3 {A
fourth brilliant idea, but by now, lots of things win for White.} Qd7 42. Qg1+
d4 43. Qg5+ Qd5 44. Rf5 Qxf5 45. Qxf5+ Kd6 46. Qf6+ 1-0

A defeat over the board can sometimes be shrugged off, but this one must have really got to Steinitz. And together with Lasker's decision to fight on the swampy ground of queenless middlegames, it toppled Steinitz. "The thinker", said Lasker, "has been defeated by the player".

There is a lot of debate about how much Lasker used 'psychological' strategy in his play. But there is no doubt how important in chess is mental toughness.