We had a top spin backhand drop shot last week, the first of the 'Shots that don't exist' series. Here is now another one from the same match, Ramy Ashour vs. Daryl Selby, first round of the 2012 British Open.
In fact, it's not true that these shots don't exist, they are just not very common. Whilst the top spin drop shot from last week is rather just a flashy thing, I deeply believe that the cross-court kill-nick that Ramy is displaying in the below video is really efficient - notwithstanding being way too underrated, under-considered and under-trained.
To go for this cross-court kill-nick, you will have to wait for a semi-loose ball from your opponent around the back of the service box (similarly as for the attacking boast). If the ball is too tight, you can't swing freely to go for it, whereas if the ball is too loose towards the middle of the court the angle is reducing and it is tougher to find the nick (and there are also other better shot-options in this case). However, if you play it from the right angle, then it doesn't even have to find the nick perfectly; it might not become a winner, but it will make your opponent stretch and scrap it off the floor just before the second bounce. Another important factor is the heights of the ball: you can only go for this shot if it bounces at least around hip-heights. And you have to make sure to find the side-wall first and not the floor (in case you miss the perfect nick); if the ball bounces first on the floor and then on the sidewall, it will decelerate it and make it bounce high whereas if you find the sidewall first it will result in a quick and short double bounce on the floor (unless you fail it completely by hitting it way too high). Anyway, you will have to practise this shot before employing it reliably in matches, and I suggest you start on the forehand side (most of the non-professionals - the writer of these lines included - will never be capable to play it on the backhand side),
By the way, I think Ramy has learned this shot from Amr Shabana, the only other player to use it on a regular basis over the years. And this is a story for itself: the more you are a 'genius' the less you are shy to learn from the others. Both Ramy and Shabana are assiduous watchers/learners (as you can also hear it in this lovely video).