deep dive into study of chess combinations ... trying to eke out the best ...

sources:

Encyclopedia of Chess Combinations
Combinations in the Middlegame
1001 Winning Chess Sacrifices and Combinations

ECC 1 ~ Combinations with attack on the king
ECC 2 ~ Combinations to achieve equality
ECC 3 ~ Other combinations

ECC a ~ Annihilation of defence
ECC b ~ Blockade
ECC c ~ Clearance
ECC d ~ Deflection
ECC e ~ Discovered attack
ECC f ~ Pinning
ECC g ~ Demolition of pawn structure
ECC h ~ Decoy
ECC i ~ Interference
ECC j ~ Double attack