It is not very often that you get to watch a play in which the two lead actors switch roles every night. It’s rarer still to be able to watch both performances and then compare how the actors approached the characters. Yet that’s exactly what you are able to do with The National Theatre’s 2011 play Frankenstein.

Last week, I went to an encore screening of Frankenstein, that featured Benedict Cumberbatch (Sherlock, The Imitation Game, Third Star) as The Creature and Jonny Lee Miller (Elementary, Endgame, Eli Stone) as Victor Frankenstein.

Yesterday, they showed the play with reverse cast,which means that Benedict Cumberbatch became the mad scientist while Jonny Lee Miller became his creation.

It’s amazing to see two takes on the same role. While both have the set script and actions to adhere to, the way they portray their characters differs greatly.

Cumberbatch’s Creature has speech patterns and movements that come close to those of the mentally handicapped. His movements remain jerky throughout his performance. and his creature suffers seizures. It takes him nearly ten minutes to stand up for the first time, and it looks so real you feel like you are watching someone who has been in an accident or suffered a stroke take their first steps again. It gets so uncomfortable to watch without being able to help, that you might end up squirming in your seat.

Miller’s performance is more child-like in comparison. After initial problems with balance, his Creature seems to get to his feet more quickly, the movements and speech generally more fluent. The way Miller portrays the Creature is reminiscent of a toddler learning to walk and talk.

As Frankenstein, Jonny Lee Miller is brilliantly cast. While he seems more human than Benedict Cumberbatch’s Frankenstein, Miller does manage to pull off the madness in Victor better. Benedict Cumberbatch’s Frankenstein is colder, socially more inapt.

Cumberbatch has slightly better comic timing and the expressions to match it. His Victor gets a few more laughs than Miller’s just because of his evident confusion when the Creature starts to argue. While this cold and calculated approach is perfect for portraying Victor the sociopath, Miller has that wild quality to him that gives him the edge as Victor the mad scientist.

Having the lead actors switch roles on a daily basis was a genius idea by director Danny Boyle (Trainspotting, Slumdog Millionaire, 127 Hours) and writer Nick Dear. This not only avoided routine setting in as each night would be different, it also gave both actors a respite from the very physical role of The Creature. Alternating between master and monster also allowed Benedict Cumberbatch and Jonny Lee Miller to show off their full potential.

Verdict: Both actors manage to captivate the audience in both roles and you are guaranteed a theatrical spectacle whichever version you choose to attend. (If you are attending a show with female friends, it also helps to know that both actors have nothing to be ashamed of while crawling around the stage essentially nude  and both look rather dashing in Victor Frankenstein’s suits…)

But if you have to choose which one out of the two versions to watch, choose to see Benedict Cumberbatch as the Creature (billed as Original Cast in Germany) for a true master class in method acting.