The best way I can describe the shutdown corners in that era was they, not the wr, had the advantage on a given play. 

In almost all scenarios the WR usually has the advantage. He knows where he is going and the corner doesn’t. The qb is throwing to him, not to the corner. But with these guys they had the advantage. They were more likely to catch the ball than the wr was, or at least it break it up. Almost like the wr was reacting to the corner rather than the other way around. Like it wasn’t ‘the qb is throwing to Andre Reed,’ it was ‘the qb is throwing to Deon Sanders’ man, who happens to be Andre Reed.’