Math Hulk X: Close Combat Powersword Sergeant vs Genestealer

The powersword sergeant in close combat with a genestealeris a pretty interesting problem from a game theory point of view once you combine parry and guard into one decision tree. To start simply, we will start with just normal combat and parry. The sergeant should of course parry anytime he is losing if he is not on guard. The question comes when to parry in cases of a tie. The cutoff point is about 5. If the stealer has a 5 or better on the high die use the parry otherwise hold the tie. Unfortunately sometime parrying will do you no good if the genestealer has a second die that is the same as his high die. In this case you do not want to parry on a tie since it gains you nothing and has a chance of killing you. Using these cut offs the sergeant with powersword will win 46.72%, tie 17.05% and die 36.23%. These odds are still good enough for the stealer player to throw stealers at him since a dead marine is not replacable unlike a dead stealer in most missions.

When both Parry and Guard are active things get really complicated. You must first decide to parry. As always you take your win if you have already won. Next you need to consider whether having him reroll his high die will on average make it harder or easier to beat him. If his high die is 6 have him reroll everytime, if his high die is 5 and he does not have double 5 also have him reroll. If you are losing on a 4 and he does not have a double 4 have him reroll but hold a tie on a 4. If he is below a 4 I would hold that result lose or tie and try to get him with guard. Now comes the guard decision. If you are losing reroll automatically as normal. For Ties of 2 or 3 I would reroll, above 4 and above hold the tie. These rules will get a win for the marine 63.10%, tie 18.75%, and the marine dies 18.15%.

These results make the powersword sergeant about the same in combat as the normal marine with lightening claws but he has the added bonus of being able to shoot also.