Genuine query, I always believed a cannonball tackle where someone attacks the legs against a joint. So going in the side or front of the knees, possibly causing damage.

In this the case? I see people saying that any late hit on the knees is a cannonball tackle.

Front, back or side doesn't really matter if its late and on the knee joint its a "cannonball tackle", the point of contact should determine the length of ban usually the side knee ligaments are season ending sometimes.

I dont think either of those are the determining criteria, it can be dangerous contact at or below the knee joint late or otherwise.

Is it against the rules to hit the legs as third man in before the ref shouts held? or is it a morale issue.

It comes under undue pressure.

The problem is both the on field officials and the disciplinary panel haven't got a clue what undue pressure actually is, as evidenced by the fact that not only did Gareth Ellis get incorrectly sin binned but he has now been given an incorrect grade B charge. Where as a legitimate crusher tackle against Ellis himself in the cup final wasn't punished on field OR by the panel.

This is why you see massive and bewildering differences in the way the games are called on field and the charges you see given out. Some weeks you see Cannonball & Crusher tackles ignored, other weeks you see them incorrectly penalised. Look at this week alone for Cannonballs - Atkins & Isa both produce blatant ones - neither charged.

What? Does it?

It was right Ellis went for ten, Isa should have gone for ten, and Atkins should have gone for ten too.

Ellis got his arm in the wrong position and got the body in the wrong position. Not malicious but dangerous lower end of the scale.

Isa and Atkins were pretty similar,neither were the worst example, but both were dangerous and more than that, absolutely unnecessary. We lose nothing if those tackles are legislated out of the game.

Under the current rules it's not a cannonball from behind as the knees are being bent in the direction they are meant to. It's only a cannonball if the tackle is entered around the knee and from the front or side.

I believe what you say should be the rules but currently it's not, it's merely your opinion of what a cannonball is.

I assume Isa on LMS is what prompted the OP's question. That was a prime example of what is permitted in the current rules, he entered from behind. At full speed it looked terrible. Personally I hate those tackles and believe any secondary contact below the waist should be banned.

I also believe the disciplinary are far too soft on all forms of dangerous contact. The worst imo being the crusher tackle as that is potentially effecting the spine of a player.

Below the knee yes but above the knee theres no danger really.

Always thought it was a tackle into the legs and knees against the joints.
Didn't see Ellis or Atkins incidents but Isa's wasn't against the leg joints. He went in behind the knees which was not against the joints.

Correct. People either don't understand the rule, or don't want to. Wire fans still claim Hansen got away with one in the '13 Grand Final when he hit Ratchford in the waist

Not actually true that grimmy, granted it wasn't a classic cannon ball as perfected by Jeff Lima and currently done on a very thin line by Sam Powell on a regular basis. Buy the principal of it by Hansen which was collapsing the leg in an awkward fashion while two tacklers then land on top of the ball carrier who's leg goes in an awkward direction which then puts stress on the knee/ankle ligaments with the combined weight.

Hence why the Rfl changed the definition of that foul in the off season off the back of that incident.