[grey-area]

Does deep blue participate?

If not your assertion is false.

[iopq]

The best chess-playing program is Stockfish and it could give deep blue and any human a handicap and still win easily

The state of art is much better now than before

[CrazyStat]

Deep blue is 25 years out of date and far far weaker than modern chess engines.

[grey-area]

I think that strengthens the point, don't you? Deep blue could beat humans a long time ago, and it's still the case that computers don't need humans to play chess, and play it better than humans do.

[CrazyStat]

> Deep blue could beat humans a long time ago

Yes

> and it's still the case that computers don't need humans to play chess,

Sure, I guess

> and play it better than humans do.

In the sense that they can beat humans in a 1v1, yes.

But none of that is relevant to the original claim, which is that a human in the loop makes a computer play worse--i.e., that human+computer is worse than computer alone. This claim is false, as the ICCF championship demonstrates each year.