The problem with clay is that a) the bounce is lower, b) ability to slide correctly into position is important and c) the ball moves slower after the bounce giving more time for defender to recover their position
This means that someone who puts more top spin into the ball (like Nadal) and can slide properly will have more success.
Last year Nole was able to break this trend by hitting the ball cleanly near the baseline, taking the time away from the clay courters and blasted them off court.
If Andy is able to improve his sliding, and duplicate Nole baseline hugging, clean ball striking technique, then there is no reason why he can't do well on clay this year. I look forward with eager anticipation as Andy excellent results last year shows he has come to grip with the red dirt