Being alert to tactics is often like having an in-built radio. You have to be intuned to what's going around, where something doesn't feel right. No one is going to tap you on the shoulder to let you know there is a fork or pin on the board. One must train that "sixth sense" to know when to look.
On the White side of an Alekhine's Defence, I reached the following position with White to move. Black has just played 12. ... Nd7
White to Move
My tactical radar failed to go off. I failed to see that the Knight on e6 was poorly defended. I would categorise this as an "Interference" mistake by Black, for by playing 12. ... Nd7 he is removing the potential defence of the Queen with the e6 Knight.
I instead played 13. Qb3 (?) gaining tempo on b7 whilst the threat on f7 lingers. My opponent failed to see the danger and replied 13. ... Qc7 where instead 13. ... Nxe5 would have diffused the potential capture on f7.
Only then did it click for me that 14. Nxf7 was on the cards.
In attempting to convert my extra pawn, I recognised the potential for a domination of Bishop over the Knight.
By forcing exchanges, I placed my Bishop on e5, which takes all the squares away from the Knight at e8.
Thus the pawn ending is winning, because White can create two passed pawns after which Black's King can't stay in the square of both of them.
My Game Annotations and Analysis