Does Size Matter In A Fight?

Many people believe that the bigger guy in a fight always wins, while others think that skills and determination are all that matter, but the truth is that both are wrong.

Size matters in a fight, and the bigger person has an advantage. Combat skills are more important than size, but the bigger the size difference, the more significant the skill gap should be in favor of the smaller person. In combat sports, where skills and fitness levels are often very close, weight plays a significant role, which explains the existence of weight divisions

In striking and grappling combat sports and street fights, size and weight are always important, but to varying degrees. But do you know how important size is in each?

Does Size Matter In A Fight?

Size matters in a fight, whether in sports or real life. Fighting skills are a great equalizer that can negate a great deal of a size advantage. Still, the bigger man has a significant advantage in a fight between untrained or equally trained people.

This is why weight classes exist in combat sports and why professional fighters go through the agonizing process of weight cutting to gain a few pounds of weight advantage.

In addition to overwhelming anecdotal evidence, recent studies have confirmed that weight differences support competitive success.

An extensive study among 708 MMA fighters and 1392 boxers shows that winners consistently regained more weight from the weigh-in to the time of the fight than losers.

The information also indicates that each percentage body mass increase resulted in a 7% increase in the likelihood of victory in MMA and a 13% increase in boxing.

There have been instances where a fighter overcomes a significant weight discrepancy. Still, usually, this is because their skills are that much better.

Weight classes place a bottom and upper weight limit on competitors’ weight to ensure a fair fight between the two and that the winner is determined by skill and preparation rather than pure size.

Another thing with size and weight is that the heavier the fighters are, the less important the weight difference is. This is why weight divisions in boxing and MMA have smaller steps in the lower division and larger gaps in the higher divisions.

For example, MMA weight classes make 5- and 10-pound steps in between until they reach light heavyweight, where the jump from middleweight is 20 lbs. and then 40 lbs. from light heavyweight to heavyweight.

Open weight tournaments also show that, after a certain point, even large weight deficits can be overcome. With that said, all participants are at least over 210–220 lbs. Regardless of the sport, you will never see a 135-pounder win an open-weight tournament.

In the days of Pride, the likes of Fedor Emelianenko and Antonio Nogueira defeated men that significantly outweighed them, but they were both powerful heavyweights.

How Much Does Size & Weight Matter In Striking?

Is It Better To Be Bigger Or Smaller In A Fight

Weight classes were introduced in boxing to ensure fights were fair and entertaining. This created a level playing field for smaller men to compete against someone their size. So, weight and length matter greatly in boxing and striking in general.

The power in a strike comes from the combination of mass and velocity, and greater mass means more power. A lot of technique goes into a powerful punch.

It effectively uses that mass in the strike, but that doesn’t take away from the fact that having greater weight increases the potential of delivering more powerful punches. And trust me; high-level strikers know how to put their weight behind their strikes.

The study we referenced showed that a weight difference predicts a higher chance of winning and scoring a knockout. In boxing, there are more weight classes than in other sports, and boxers do not cut as much weight as MMA fighters, meaning there are fewer weight discrepancies in fights.

Having a length advantage is also a factor in striking because it usually means that the fighter with the longer reach has an advantage.

After all, you can hit your opponent from a distance where you cannot be hit. But with the weight of both fighters being the same, both can favorably utilize their reach. Except in heavyweight boxing, studies show no correlation between longer fighters and higher winning percentages.

Then, weight and size serve a purpose up to a certain point. The heavyweight boxing division has no upper weight limit, but despite that, the sport is not dominated by giants.

Weighing too much has diminishing returns after a certain point, as more mass slows you down, makes you less mobile, and causes you to tire out faster.

Long reigning boxing heavyweight champions in recent decades have all weighed between 240 and 260 pounds, with some, like Deyontay Wilder, even getting under 220 pounds.

How Much Does Size & Weight Matter in Grappling?

Grappling styles like BJJ and Judo, and, to some degree, wrestling all focus on utilizing leverage and technique over strength and power to overcome a bigger opponent. MMA and BJJ clearly show that a skilled grappler can overcome massive weight and size deficits if the opponent lacks ground fighting skills.

All of this works excellently, but only if the opponent does not have the same knowledge. When skills are similar, weight and strength suddenly become critical factors. If size and weight didn’t matter, then there would be no point in weight classes in grappling, wouldn’t it?

Severe weight cutting is a practice originating in wrestling, showing that even minor weight differences can be a deciding factor in a competition where all other factors are razor close.

Having a weight and size advantage plays across the board in grappling. The heavier man can easily hold down the lighter opponent or overpower him from bad positions.

When we talk about weight and strength in striking and grappling, we generally talk about people who train regularly and are in at least decent shape.

Strength and power bring a significantly larger advantage than dead weight, but weighing more also increases the potential to be stronger and more powerful.

Does Size And Strength Matter In A Street Fight?

Does Size And Strength Matter In A Street Fight

The popular opinion is that the bigger guy wins the street fight, and this opinion is not unfounded. If both are equally unskilled, the heavier man packs a harder punch, has a longer reach, and can use his weight and power if the fights get close.

But we must also not forget the famous saying, “It’s not the size of the dog in the fight, it’s the size of the fight in the dog that matters,” which is often very valid with untrained people (and trained people for that matter).

But once skills come into play, the size difference becomes less and less critical. A smaller man who knows how to punch and kick can not only hit harder than much bigger men but also do it with greater accuracy and timing.

Then grappling arts like Judo and BJJ give practitioners an unsurmountable advantage over all sizes, which is why they are the preferred martial arts for law enforcement personnel.

So in a street fight, the fewer skills are involved, the more size and strength matter and vice versa.

Is It Better To Be Bigger Or Smaller In A Fight?

As we’ve seen, size and weight do matter in a fight, so being bigger in a fight is a desirable advantage to have. But knowing how to use your size and physical attributes is also essential. Being tall is not enough to win.

You also need to understand how to use your range and length effectively. The same goes for weight and strength. The lighter opponent will likely be faster and have more endurance, and tactics play a significant role in combat sports.

As you will see in some of the fight examples, being smaller does not mean you will lose, but it certainly means you need to fight in a way that negates the size advantage and plays to your strengths.

MMA is so appealing because the enormous variety of techniques and liberal rules allow for just as many tactics and ways of fighting, meaning every person can figure out how to use his build, be it small or big, to his advantage.

Famous David vs. Goliath Fights

As much as size matters in a fight, it is not everything. If it were, sumo wrestlers would dominate all combat sports, and fighters like Akebono and Zuluzinho would have been undefeated.

People love the underdog story and see small people beat up bigger people. Some of the most famous myths in the world, like David vs. Goliath, show us this fascination is not something new.

There have been more than a few fights in combat sports pitting fighters with extreme weight differences against each other. The Japanese especially love such freak fights and have had quite a few in the K-1 and Pride glory days. Here are some of the most famous David vs. Goliath fights.

Genki Sudo vs Butterbean

This fight is a classic example of what early MMA demonstrated. When a striker meets a grappler who has no knowledge and skills on the ground, he will get submitted, regardless of his size. Then, if this were only a striking fight, Genki would get obliterated.

Fedor Emilianenko vs Zuluzinho

This fight is an excellent example that the size difference is not that advantageous once you enter heavyweight. Many fighters have proven that across all combat sports.

Fedor Emilianenko had dynamite in his hands and could knock out any man on the planet. But can a 135-pound fighter knockout Zuluzinho? I am not so sure about it.

Kaolklai vs. K-1

Thai fighter Kaoklai’s feat may be the most impressive of all small vs. big man fights. In almost all of the fights where smaller men like Royce Gracie, Genki Sudo, or Ikuhisa Minowa have defeated goliaths, they have done so by submitting them on the ground.

But 150-pound Thai fighter Kaoklai defeated men almost twice his size in kickboxing and did so in impressive fashion.


Size matters in a fight, and the bigger fighter has an advantage. They can put more weight behind their strikes and use their weight to get the upper hand in wrestling exchanges.

Fighting skills equalize a lot of size disadvantages, and smaller people can easily beat larger ones both on the feet and on the ground if they are more skilled. But in combat sports, where skills and fitness are relatively close, weight plays a large role, which is why there are weight divisions. 


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