Bro, it doesn't matter that he outweighs you by 70 pounds, you do BJJ...

I understand where the romantic notion comes from. The one where people think anyone who does a martial art can beat people twice their size in mortal combat. I grew up watching Kung Fu movies where a tiny master took out six guys with one hand and then made a witty comment (your Master should have taught you respect).

 I was in awe when Royce Gracie beat Dan Severn when I watched the fourth UFC in 3rd grade.

Royce beating dudes...

When I heard BJ Penn fought at heavyweight, it only further reinforced the idea that all martial artists can beat up anyone (regardless of size).

Penn vs Machida

 Let it also be known that I am not a big guy. I am about 5'8" and weigh around 160 pounds. It has been my experience in all of the sports I have played and the few fights I have gotten into, that size matters.

Picture of Jeff Curran, Marcelo Garcia and me, to help you gauge my size...and remind you I hangout with Jeff and Marcelo

I am stubborn though and held onto the belief that someday I would learn a martial art and pummel men much larger than myself. As a senior in college I took Hapkido, then Judo and Sambo when I moved to Kansas City. Finally, I ended up in Waterloo, IA and landed at a great BJJ gym. I now have around 6-7 years of BJJ experience and about 10-11 years of martial arts/grappling. What follows below are my heartfelt words on the role weight/size plays in BJJ, grappling and fisticuffs.

To start, size matters. If size didn't matter, there would be no weight classes in the UFC, BJJ tournies, etc. However, skills can certainly overcome size disadvantages. Case in point, every once in awhile we have a new, strong, young lad come into our gym. Typically, they have a lot of wrestling experience and feel like they are going to run through everyone we train with. It has become our time-honored tradition to find a smallish, white belt (the dorkier looking the better) and deem them our "gatekeeper." His or her job is dispense humble pie to all jerks who darken our door step. When it comes to an unskilled combatant against a skilled BJJ practitioner in a controlled BJJ gym, size doesn't matter that much. On a side note, I once held the gatekeeper title because there is nothing more deflating than a soft, middle aged, college professor dealing out punishment.

Check out Riley Breedlove tooling high school wrestlers in a park. 

When it comes to the effectiveness of BJJ on the streets, it is also pretty useful for people of all sizes. Luckily (and to my low-key disappointment) I have never had to use my "jitz" in a real fight. But, all you need to do is look up videos online or check the BJJ message boards. Given the option between wildly throwing haymakers and/or trying to tackle someone when I have little to no experience, I would rather have the BJJ on my side. With that being said, you never know who is getting into a fight with you. They might have trained forever, maybe they are a golden gloves boxer, maybe they are an X-Men (probably the least likely scenario).

If I was an X-Men I like to think I would be Nightcrawler 

 If you are looking to get into BJJ just to kickass at the bar, maybe you should instead just go to AA.

Watch this video, it is worth it. 

When Jiu-Jitsu meets Jiu-Jitsu is typically when size advantage plays the largest role. Yes, there are some great instances of smaller BJJ players beating bigger opponents (Marcelo vs Ricco Rodriguez or Makenzie Dern vs Gabi), but most of the time a bigger competitor wins the absolutes at a large international tourney.

Marcelo vs Ricco

Mackenzie Dern vs Gabi 

2013 road to ADCC absolute for Cyborg

In my personal experience, skill greatly compensates for a size advantage. We have several newer blue belts who are much bigger than me and I can hold my own. However, we have a brown belt who is close to my size and he absolutely railroads me. There is a purple belt at another school who I am 25ish pounds heavier than and I can typically control him because of my extra fluff (that is what I call my "Dad-bod" parts).

In an extremely simplified sense, skill can make up for weight/strength deficits and weight/strength can make up for skill deficits. I try to use this to my advantage by always saying I weight less than I do, and asking for the weight of a person who tapped me. If there is more than a 10 pound difference, I blame it on their girth and get to keep my ego.

In short, if you are looking to do BJJ because you think you will become a Super Sayian who can beat people 5 times your size, you will be disappointed. But, if you want to take BJJ to improve your confidence, feel more safe if in a dangerous situation or hopefully get a chance to tool "d-bags" that get off on pushing around little guys/girls, you are in the right sport. Just remember, the ability/right to beat people bigger than you is earned from years (and I mean years) of getting beat on that mat, it is not a training montage type of thing.