Hey, I'm Winning! Now I Can Relax - NOT! (LCCC Still Dark - Due to C-19)

IM Yates (White) vs GM Tartakover (Black) - Hamburg, 1927

Having a winning position in a chess game is a great feeling. But sometimes you can feel too good and lose your focus.
Is there a psychological reason for this? Yes, as we all tend to let our guard down when we no longer perceive any danger. We all tend to relax when no threat seems imminent.
But, in chess that is rarely the case even in dominating positions.
We also tend to want to 'finish things up'. In our minds we are screaming "Look pal, this game is over. You are toast! Resign already. I want to go grab a sandwich and get ready for the next round."
And it can be especially true if you have been playing for a long time before getting the advantage or have been building an ever bigger advantage over time.
Look at the position here, as played by two very strong chess masters. Black has a big advantage both material wise and position wise.  According to Igor3000 the lead is the equivalent of 11 pawns (-10.9)! An overwhelming advantage.
But the GM was frustrated that his opponent had not given up yet and decided to end things quickly.

1. ……          Qxb4?
Black gives up his queen to eliminate White's last defender while winning a pawn (-2.2)and is sure his extra pawn will bring his queen back to life to win the game

2. axb4           axb3
3. Kb2            Kc4
4. Ka3            ........

Black to make move #4

 None of this was a surprise to GM  Tartakover. He had seen all of this. He also saw that if he plays 4. …Kc3, it is a stalemate.
Tartakover saw that 4.....b2 5. Kxb2, Kxb4 is a win for Black. So, 

4. ……            b2
5. Ka2!
But White had one other legal move available to him and he took it!
Now the game is a book draw.

GM Tartakover was guilty of shutting down his full analysis of the position and getting in a hurry to win a won game.

LCCC Still Dark, But Here is a Lively Game!

Position after Black's 14th move ........f5

Here is the position after fourteen moves. Games with Kings castled on opposite wings usually lead to fireworks. Who can get there first is usually the strategy. Here is no exception. Both sides go for the win.

15. exf5             g6
16. f6                h5
Black is two move late. This move was better played at move 14 instead of the f5 actually played. White is up a half-pawn positionally (+.5).

17. Qg5?          …....
A small error as 17. Qe4,  h4 18. Ne3 kept White in the lead. Game even.

17. .......            Bh6?
Black would do better to block the invading pawn with 17. .....Qf7 first. White back on top by that half-pawn.

18. Qxg6          Qh3?
As stated, Black is all about the attack, but this is premature. 18. ......h4 was more to the point. White is up the full pawn now.

19. f7?             ........
White is also on full aggression mode and gives his extra pawn a little too much credit. It's not getting to the end zone for a while yet. Meanwhile Black is making threats, and it is never ever wise to ignore your opponent's moves. 19. Ne3 was needed. The game is back to even again.

19. .......           h4
20. Ne3??        hxg3?!
This is one move too late! 20. f4 was needed to keep White alive! 20. ...hxg3 21. Qxg3, Bxf4 22. Qxh3, Rxh3 23. Rael and White is actually up a fifth of a pawn (+.2) instead of down (-1.5)! Black has a more accurate 20. ....Qh5 21. Ng4 Bf4. So now Black is only up (-1.2), but still with an advantage.

21. Qxg3         Qe6
22. Kh1??        Bf4
Getting out of the probable rook pin on the White King and Queen with Black playing Rg8 at some point was admirable, but 22. Qf3, Bf4 23. Ng4 kept it a game. Black is up now over 6 pawns!

23. Qg4           Rxh2+
24. Kg1           Qxf7
25. Qf3            Rg8+
26. Ng4           Qd5!
27. Rfd1          Qxf3
28. Rf1            Qxg4 mate