Slide Tackle Logic Explained

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Slide Tackle Logic Explained

Postby John Wilson » Fri Feb 15, 2008 9:06 am

While poking around in the KO2 code recently I was looking at the ball possession mechanisms (for the optimistic tactics mod. to FWCV).

After a little further digging I have found the reasons for unintended slide tackle 'incidents' and will attempt to explain them here as hopefully it should allow the KOA to make a more informed decision regarding rules around this feature – if you are impatient or have a headache, you’re probably better off skipping to the end as it’s a bit of a mind f*ck :wink: .

I’ll have to explain the ball possession mechanism first as that is what determines whether slides will occur or not.

Possession Mechanism
The main affect this has on the game is: a slide will only occur if the opposing team has possession and your player does not

Firstly, there is no direct connection between who has possession of the ball and what player is displayed in the corner of the screen
There is obviously some relationship – i.e. if a player is dribbling he has possession but this is not enforced by the code

There are two possession variables, one for each team. In theory, it is possible for a player in each team to have possession of the ball simultaneously but this is very rare and has no effect on slide tackle logic - so the normal states are:

  • No player has possession (this is the usual state when the ball is not being dribbled)
  • A Player on Team A has possession
  • A Player on Team B has possession

How possession changes:

  • No Possession -> Player Has Possession
    This change occurs if a player touches the ball or picks it up (‘keeper or for a throw in).
  • Player Has Possession -> No Possession
    If a player kicks (including free kicks and penalties but not passes), chips, slides into or heads the ball this will ensure nobody has possession.
    If a player is dribbling, but doesn’t get near the ball for 6 seconds then his possession is removed
  • Player Has Possession -> Different Player On Same Team Has Possession
    If a pass or throw in is executed, the ‘target’ player takes possession as soon as the kicker or thrower releases the ball.
  • Player Has Possession -> Player On Other Team Has Possession
    If a player without possession gets near enough to the ball he will take possession

    If a player without possession gets near enough to the player who has possession a ‘challenge’ will occur as described later. Note that the location of the ball has no effect on this, if the player with possession has let the ball dribble away loosely and nobody touches it he will remain in his possession and so can be challenged.


Explanation No. 1 - The Unintended Slide when nobody else is anywhere near the ball:
A ball in open play can remain your opponent’s possession (and therefore cause you to slide) if:

They have been dribbling the ball and have let it run free – it will remain in there possession for up to 6s – an age in KO2 terms!
A pass has gone astray – the target of the pass will remain in possession for 2s if nobody touches the ball
A throw in goes astray – the target of the throw will remain in possession for 2s if nobody touches the ball

…ok, that one was pretty obvious and it’s easy to work around as there’s nobody around you and you just have to touch the ball before trapping.

Explanation No. 2 - The Unintended Slide when a defender is near
The other instance is when you are pressured by an opponent and you just know what’s going to happen if you try and trap it. This is related to the challenge mentioned above – the important thing to note is that you or your opponent don’t need to be near the ball for you to lose possession, you’re opponent has to be near you.

So from the point of view of the challenger

Code: Select all

if(opponentInPossession is within 4 ft of me) { // note: within 8ft if the challenger is CPU controlled
        //
        // Attempt a challenge…
        //
        if(opponentInPossession.speed == 0) {
                takePosession()!!
        } else if(me.speed > 0) {
                // depending On Player Direction barge a player
                //  or knock over if defending skills are better
        } // …else me.speed == 0 so do nothing
 }


The crucial condition here the fact that the opponent will always take possession if you centre the stick – no matter if you are between him and the ball or even if the ball has run a good distance away from you both. The moment you get near the ball and try to trap a slide will occur!

Hence, players who try to give themselves space to trap the ball by pausing briefly will suffer from this effect much more than a player that has the ability to trap the ball while running full tilt.
The most obvious case is when an attacker is running up field with a defender immediately behind him, the attacker pauses very briefly before trapping at which moment the close defender will invisibly take possession, causing the attacker skid impotently into the ball :?

Although I have not done extensive testing, I tried a game last night armed with this new knowledge and was able to confidently trap the ball everytime.
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Re: Slide Tackle Logic Explained

Postby Stainy » Fri Feb 15, 2008 11:22 am

The most obvious case is when an attacker is running up field with a defender immediately behind him, the attacker pauses very briefly before trapping at which moment the close defender will invisibly take possession, causing the attacker skid impotently into the ball


Thats all you needed ;) no seriously... excellent work.. I understood everything you put down there...

Now.. armed with this knowledge and my new controller... I shall be.................. :mrgreen:
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Re: Slide Tackle Logic Explained

Postby gdh82 » Fri Feb 15, 2008 1:01 pm

Wow! Impressive piece of "mind-f*cking" research! :eeko: 8)

John Wilson wrote:Firstly, there is no direct connection between who has possession of the ball and what player is displayed in the corner of the screen


I feel f*cked already! :yikes: :lol:

John Wilson wrote:The crucial condition here the fact that the opponent will always take possession if you centre the stick – no matter if you are between him and the ball or even if the ball has run a good distance away from you both. The moment you get near the ball and try to trap a slide will occur!
Hence, players who try to give themselves space to trap the ball by pausing briefly will suffer from this effect much more than a player that has the ability to trap the ball while running full tilt.


Very interesting - I was expecting the unintended slide to occur whether the stick is centred or not - so will gladly try this out.

I still seems to me at least that this possession logic has a negative impact in terms of reducing the possibilities in play, whereas the CV switch allows for more positive possibilities and ultimately more fun!

Having said that, this very interesting KO2 information give us all better understand the great game so thanks for taking the trouble to post! :)
Last edited by gdh82 on Sat Feb 16, 2008 8:19 am, edited 1 time in total.
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Re: Slide Tackle Logic Explained

Postby Steve Camber » Fri Feb 15, 2008 1:58 pm

Professional! :D
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Re: Slide Tackle Logic Explained

Postby John Wilson » Fri Feb 15, 2008 3:13 pm

gdh82 wrote:Very interesting - I was expecting the unintended slide to occur whether the stick is centred or not - so will gladly try this out.

...the unintended slide can occur whether the stick is centred or not. It is the fact that the challenging defender will gain possession if you stop (however briefly) while he is near. Once you start moving again he will still retain possession (as long as he keeps moving of course) and that can only mean one thing when you hit the fire button: you'll be down on your arse :lol:

Steve Camber wrote:Professional! :D

...thanks!

For the record, I found no actual bug that causes the unintended slide, it's just a side effect of the way the possession mechanism is implemented. So if the KOA deem that unintended slides should be a thing of the past, then I think Steve's addition logic (i.e. don't slide if you are the nearest man to the ball) is the simplest and most elegant way to implement the enhancement.
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Re: Slide Tackle Logic Explained

Postby Setzer » Fri Feb 15, 2008 3:23 pm

Nothing to say but one word : headache :mrgreen:

Thanks for the explanation ; )
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Re: Slide Tackle Logic Explained

Postby Bounty Bob » Sat Feb 16, 2008 12:16 am

John Wilson wrote:...the unintended slide can occur whether the stick is centred or not. It is the fact that the challenging defender will gain possession if you stop (however briefly) while he is near. Once you start moving again he will still retain possession (as long as he keeps moving of course) and that can only mean one thing when you hit the fire button: you'll be down on your arse :lol:
So does that mean that if I am running, then hold down the button to trap the ball and keep the stick held forwards, the unintended slide will not happen?

But if I keep the button held down after centering the stick, then I'll lose possesion and slide?
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Re: Slide Tackle Logic Explained

Postby Stainy » Sat Feb 16, 2008 7:18 am

So does that mean that if I am running, then hold down the button to trap the ball and keep the stick held forwards, the unintended slide will not happen?

But if I keep the button held down after centering the stick, then I'll lose possesion and slide?


Heheh so keep these two things in mind tomorrow!! thats all you need!! :lol:
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Re: Slide Tackle Logic Explained

Postby John Wilson » Sat Feb 16, 2008 11:56 am

Bounty Bob wrote:So does that mean that if I am running, then hold down the button to trap the ball and keep the stick held forwards, the unintended slide will not happen?

But if I keep the button held down after centering the stick, then I'll lose possesion and slide?


...you lose possession if the stick is centred and a defender is near.
So, if you do that and then subsequently hit fire without first touching the ball to regain possession you will slide.

Similarly, if you are running and holding the button down with the intention to trap (again with a defender near by), a slide will occur if the stick is centred without releasing the button first.
This one used to plague me - I thought maybe there was some bug that caused a slide at the point a trap should occur. But no, it was because I would centre the stick when I was on top of the ball in anticipation of the trap occuring. I would do this only by the tiniest fraction of a second but it was enough to trigger the change in possession.

Please try it. I played lots of games last night (after reading Robert's 'n00bs beware' post :shock: ) and beating the unintended slide with the might of your own joystick is revelation.

...although I don't know why I'm telling you this today - I'm sure you'll slot at least 6 past me tomorrow :lol:

Stainy wrote:Heheh so keep these two things in mind tomorrow!! thats all you need!! :lol:

...as I understand it this feature will be turned off tomorrow anyway.
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Re: Slide Tackle Logic Explained

Postby Steve Camber » Sat Feb 16, 2008 12:28 pm

Garry, enable the joystick inputs on replays, and do your thang!! :D

Or dig up some of your old slide vids to confirm this theory.
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Re: Slide Tackle Logic Explained

Postby gdh82 » Sat Feb 16, 2008 1:25 pm

Steve Camber wrote:Garry, enable the joystick inputs on replays, and do your thang!! :D

Or dig up some of your old slide vids to confirm this theory.


:) This is an old vid....(sorry about poor quality)



I shall be looking into this, next time I meet up for KOBRA bro's ...
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Re: Slide Tackle Logic Explained

Postby gdh82 » Sat Feb 16, 2008 1:43 pm

And here's another old one...

WARNING: CONTAINS SCENES OF AN AUTOSLIDE-&-UNINTENDED-SLIDE-F*CKER NATURE THAT YOU MAY FIND OFFENSIVE!

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Re: Slide Tackle Logic Explained

Postby Bounty Bob » Sat Feb 16, 2008 6:10 pm

gdh82 wrote:
Steve Camber wrote:Garry, enable the joystick inputs on replays, and do your thang!! :D

Or dig up some of your old slide vids to confirm this theory.


:) This is an old vid....(sorry about poor quality)



I shall be looking into this, next time I meet up for KOBRA bro's ...
In the first example, it looks like the joystick direction indicator disappears briefly. In the second example, the arrow definitely seems to be on the whole time.

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