Stop Defense. Well I kinda liked this card before, but now all it really does is take up deck space. Don’t get me wrong, it’s a nice card, but the majority of the time, the monsters are gonna be face down, thus you activate their effect. The only time I played it was when there was no monsters on my field so their Bug would kill itself and not me. Most people won’t play high def monsters like Aqua Madoor or Giant Soldier of Stone, as Wall of Illusion, Man-Eater Bug, and Hane-Hane are much better choices, as they come with effects. Not to mention, more monsters have greater attack points, so you’re just making it harder to kill. =/ It’s a wonderful sideboard card, however.

Stop Defense:

Causal play: 3
Tourney Play: 3.5

Pros:

-Makes a high defense monster easy to kill...
-Gets rid of Man Eater bugs

Cons:

-Wastes space
-might not be a defense monster

RFP(Reasons for pros)- Well say they have a Giant Soldier of stone and you want to kill it right then and there all you need to do is stop defense it. 

Then almost any of your monsters could kill it which is nice. Also it brings you one step closer to winning the game. Also say you suspect your oppenent has a Man Eater bug you could use this thing to flip it over, and then the man eater bug would destroy itself. Or if its not a man eater bug then you could just do some damage attacking there defense monster.

RFC(Reasons for cons)- Well one of the few cons is that it wastes deck space for other cards you might need. Like say you have to choose between this card of card destruction. You'd be losing one or the other. Sure you could go both, but you want to keep your deck as close to 40 as you can. So usually you wouldnt have room for both. Also sometimes I do this. I play a trap hole down... then I play a la jinn the mystical genie in rv defense mode. Mind you this is first turn. If your oppent uses stop defense on my la jinn thinking it is a man eater bug or wall of illusion or any other defense monster for that matter they could hurt themselves. So sometimes if your oppenent is daring they could put a high attack mon in defense turn 1 and then you would just activate there attacker with stop defense. 

Combos:

- Fissure + stop defense you use stop defense oh look it is a wall. Then you use fissure get rid of the wall and hope they dont have a trap hole and attack for direct damage with a monster.(unless they have wabuku. 

-Stop defense + attacking mon well this is the most obvious one. I mean you use stop defense then attack your oppenent with your mon and they take damage.