Tyrannofex v Trygon

Howdy and good morning to everyone. Everyone knows Tyranids are lacking on ranged anti-AV13/14 weaponry. We've got great transport poppers, sadly taking up a very valuable Elite slot, but still great transport poppers in Hive Guard. However above AV12 we really have nothing to reliably pop transports from range. We do have broods of Zoanthropes but any Psychic Hood or Psychic protection is going to make the Zoans either kill themselves or render them useless...and most competitive lists that can take Psychic protection do.


Bring in the Tyrannofex.


The Tfex is known for it's rupture cannon. Str10 48" range 2 shots and AP4. Now this weapon is sadly fired at a BS3. There are many different arguments for the Tfex such as:

1) BS3 doesn't matter. Think of it as a twin-linked weapon that may have a chance to hit twice.

2) At a 2+ armor save this beast will be firing all game.

3) The option to fire at 48" range with S10 is amazing and can pop Nob Bikers and Thunderwolves.

The list goes on and on....

Sadly these reasons don't do it for me. Let me lay it out in an easy to read and assess format. But before I list my reasons why I prefer not to use the Tfex I want everyone to know this is just my opinions and reasoning behind it. I am not saying this is deadset and that no one should ever use the Tfex at all. I am also gauging my opinions on a Tfex that is primarily to be used as Anti-AV. The Tfex has great anti-infantry weaponry available but if I am taking a Tfex it's going to be for anti-AV. We have plenty of anti-infantry in everything else in our Codex.

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Here is some mathammer before I list my points:

2x Tfex's shooting at AV14 with cover: (Double effects to get results without cover)
Shak : 13.182%
Stun : 8.077%
Weap : 8.077%
Immo : 8.077%
Wrec : 5.441%
Expl : 5.441%

2x Tfex's shooting at AV13 with cover: (Double effects to get results without cover)
Shak : 15.654%
Stun : 10.657%
Weap : 10.657%
Immo : 10.657%
Wrec : 8.077%
Expl : 8.077%

1x Trygons assaulting AV14 that moved 12":
Shak : 28.441%
Stun : 19.031%
Weap : 19.031%
Immo : 19.031%
Wrec : 13.941%
Expl : 13.941%

Calculation: (This calculation was done by Atnoslen from TyranidHive)
Destroyed Probability for 1 shot=(# of dice faces that hit)/6*(# of dice faces for Penetration)/6*(# of dice faces for destroyed result)/6

Thus for TFex with BS 3 hitting on 4+, penetrating on 5 & 6, and destroying on a 5 & 6: 3/6*2/6*2/6=5.56%

Binomial distribution for a success with 2 shots given probability of 5.56% = 10.80% chance to destroy in one turn.

Binomial distribution for a success with 6 shots over 3 turns given probability of 5.56% = 29.03%.

Compare to being in cover the entire time (3 turns): 15.55%

Over the game (5 turns), assuming the TFex lives, there is a 43.47% chance for 1 TFex to destroy an uncovered AR14, and only a 24.55% chance for a covered AR14.

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-A smart opponent will usually ignore the Tfex: What? No smart player will ignore it! I have to say that the only player that won't ignore the Tfex is a player that doesn't know the chance that a Tfex actually has at destroying an AV14 vehicle. A smart opponent that knows the chance a Tfex has to impact a game is so low will ignore it and focus on more immediate threats right? Like that brood of infiltrated 20x Genestealers with Toxin Sacs. (Great suggestion by hyv3mynd that I've been using and having great success with! Here's his blog http://synaps3.blogspot.com/) 

If you have only fought opponents that constantly try to take down the Tfex then you will have good success with the Tfex because those shots aren't taking down your Tervigons or Flyrants or Harpys etc. Thus allowing them to get into the opponents face and smash it in. Now if you fight opponents that know to ignore your Tfex now you are truly set back because not only are you firing a 265 point model for 5 turns with only a 24.55% chance to destroy a covered AV14 vehicle and it's not doing it's intended job but now your other MC's are dying and not fulfilling their job.

-It's low chance of actually doing something to AV13/14: See math hammer above. Now remember we are talking about using the Tfex as anti AV13/14 primarily. Yes we know it has great anti-infantry shots but if your firing at AV13/14 then those shots are wasted.

-Cost: 265 points with a Rupture Cannon. That is a hefy amount of points to be put into a model with such a low capability of doing what it is taken to do. If it was priced around the Trygons points then I would be more acceptable of the Tfex.

-Talking about the Trygon, other great options. The Trygon will 90% of the time draw fire from your opponent leaving your other MC's capable of doing what they need to do. With that said a Trygon still has a fairly good chance at surviving considering FNP + Cover Saves. Yes it's tough to give a Trygon Cover saves but with Tervigons, Dakkafex's (or CC Fexs) or Venomthropes in the list and FNP it makes them much more survivable.

Let's mathammer some shots from 15 Missle Launchers per turn. 

Best case scenario is 4+ Cover Save and FNP: 34.7% chance to kill a Trygon

4+ Cover Save: 69.4% chance to kill a Trygon

5+ Cover Save and FNP: 46.3% chance to kill a Trygon

5+ Cover Save: 92.6% chance to kill a Trygon

Just with FNP: 69.4% chance to kill a Trygon.

Nothing: 138.9% chance to kill a Trygon. (LOL!)

So unless you take no precaution at all to you should have a fair chance to have the Trygon survive at least one round of shooting. Now your other MC's are still doing their job and alive. Or they ignore the Trygons and well...we all know what Trygons do when they are ignored. :)