If you're a small player attempting to take down someone bigger than you, you can't be scared of them hitting you or injuring yourself if you put in the big hit.
Sonny Bill Williams facts
Date of Birth: 3 August 1985
Place of Birth: Auckland, New Zealand
Height: 6ft 3in
Position: Loose forward
NRL Club: Canterbury Bulldogs
Previous club: Marist Rugby League Club
International debut:v Australia, April 2004
If you fear going into a tackle, you're more than likely to injure yourself because you're not going to get the technique right.
Make sure you go in fully committed because if you don't, you're bound to come off second best.
You have to go into a tackle in the right frame of mind - keep thinking to yourself "I'm going to stop this bloke".
One of the most important things to remember is getting your technique spot on.
So aim for the waist or the thighs.
For me, one of the best feelings in the world is making a big hit and getting praise from the boys on the field.
That's why I love this sport, it gives me such a huge buzz.
But I also get that same feeling whenever I make a big hit or a break or a run.
We practise our tackling with big bags, so we don't really make the big hits on each other in our training sessions.
We do a lot of defensive drills which helps us develop our technique - but we save our big hits for the big games!
One of the most important tackles I've ever made in my career was in the NRL Grand Final against Sydney Roosters in front of a packed crowd in Sydney.
Eric Grothe: Big hits a speciality
We were camped on our try line and I made a big hit on Australian full-back Anthony Minichello, knocking the ball out of his hand, giving us possession of the ball with only a few minutes to go.
We only had a three-point lead too, so that was a really good feeling.
The biggest hit I've had in my career so far is from a player called Eric Grothe who plays for the Parramatta Eels.
He's a winger but he's pretty strong. I certainly remembered his big hits!