For each class, what are efficient methods to destroy the Tank Robot?

Solution 1:

Ok, I did some calculations for the sniper.

First, let's consider rifles. There is always the basic version, and the fully upgraded version. We are talking about killing the tank, so upgraded means full damage, faster recharge and faster reload, as well as maximum ammo capacity. Since the damage is subject to some randomness, I averaged the lower and upper bounds each to get my values. I also assume perfect reflexes for firing as soon as the charge reaches 100%, and the auto-rezoom feature enabled.

Sniper rifle:

• Unscoped basic weapon: 33 dps (down to 24 with 15s to find new ammo)
• Scoped basic weapon: 35 dps (down to 31)
• Unscoped upgraded weapon: 107 dps (down to 85)
• Scoped upgraded weapon: 128 dps (down to 116)

Huntsman:

• Unscoped basic weapon: 26 dps (down to 16)
• Scoped basic weapon: 41 dps (down to 29)
• Unscoped upgraded weapon: 84 dps (down to 60)
• Scoped upgraded weapon: 140 dps (down to 109)

Sydney Sleeper:

• Unscoped basic weapon: 33 dps (down to 24)
• Scoped basic weapon: 40 dps (down to 34)
• Unscoped upgraded weapon: 107 dps (down to 85)
• Scoped upgraded weapon: 144 dps (down to 129)

Bazaar Bargain:

• Unscoped basic weapon: 33 dps (down to 24)
• Scoped basic weapon: 24 dps (down to 22)
• Unscoped upgraded weapon: 107 dps (down to 85)
• Scoped upgraded weapon: 90 dps (down to 84)

Machina:

• 0% charge basic weapon: 33 dps (down to 24)
• Scoped basic weapon: 40 dps (down to 35)
• 0% charge upgraded weapon: 107 dps (down to 85)
• Scoped upgraded weapon: 148 dps (down to 134)

Hitman's Heatmaker:

• Unscoped basic weapon: 27 dps (down to 19)
• Scoped basic weapon: 28 dps (down to 25)
• Unscoped upgraded weapon: 85 dps (down to 68)
• Scoped upgraded weapon: 103 dps (down to 93)

Conclusion: Whatever you do, use the Machina, it has the highest damage in all catgories. (40 is close enough to 41 - don't say anything!)

Now to consider melee weapons. I also assume the basic weapon as well as the fully upgraded weapon. Upgrades are damage +100% and hit speed +60%.

Kukri:

• Average basic: 106 dps
• Average upgraded: 296 dps

Tribalman's Shiv:

• Average basic: 53 dps
• Average upgraded: 150 dps

Bushwacka:

• Average basic: 81 dps
• Average upgraded: 228 dps

Shahanshah:

• Average basic: 80 dps
• Average upgraded: 222 dps

Now, while this far the Kukri would be best, you might notice that we forgot about one circumstance. If you are below 50% health you deal much more damage with the Shahanshah:

• Average basic: 132 dps
• Average upgraded: 369 dps

With that in mind, a stunning 369 average damage per second, while you never have to reload, makes the machina with its 148 dps look like a toy.

EDIT:

(I deleted the previous calculations concerning other classes' melee weapons, because I clearly made mistakes. I also corrected the melee calculations for the sniper, which were wrong, too. I have no idea what I did a couple days ago. I redid the melee calculations WITH critical hit chance of 15%.)

Solution 2:

Well both badp's answer and nrohwer's answer are very well detailed in DPS calculation, I'm simply going to list each class and a good overall strategy for each without taking into account dps calculation or specific weapons.
So my answer is more of a basic "what to do to at least do something helpful" than actual "best circumstances with best weapons".

1. Scout - Not much you can do here, try your best with your primary. When the additional forces come, such as spies or snipers, take care of them.
2. Soldier - Rockets rockets rockets! If you have the Equalizer, rocket yourself to low health and use that instead.
3. Pyro - Flamethrower until you are out of ammo, then run and get more ammo or use secondary/melee weapons. The Phlogistinator's 'Mmmmph' criticals definitely help with high DPS.
4. Demo - Grenade Launcher, and Sticky Launcher. Spam them like crazy.
5. Heavy - It costs $400,000 to fire this gun for 12 seconds.
6. Engy - Wrangled or not, your sentry is going to do good damage. I like to Wrangle it until the Tank comes within the sentry's automated range, then whack it with my wrench while it auto fires to replenish it's ammo. See other answers for best dps.
7. Medic - Equip the Kritzkrieg if you have it and Ubercharge your heavy/demo again and again and again. If you don't have this medigun, just keep healing your team mates when the reinforcements come.
8. Sniper - Use your gun or melee weapon, which ever most upgraded. Best is melee (Shahanshah with low health is ideal) but if most of your upgrades are in your rifle, use it instead.
9. Spy - Not much you can do here, try your best with your primary. When the additional forces come, such as spies or snipers, take care of them.

Hope this helps!

Solution 3:

It's strictly a problem of maximizing your damage per second. For the record, tanks have between 18,000 and 60,000 hitpoints (see details here.)

For most classes this normally means using as much of your primary weapon as possible on this bad boy. (I have honestly no idea about the role of a spy on the tank.) You probably already considered maximum damage per second in your calculations, but obviously you realize that you want to do as much damage as possible spending as little time as possible while reloading and fetching ammo.

This for example brings many demomen to prefer the Scottish Resistance to the stock Sticky Launcher for the very simple reason you can lob 14 stickies instead of 8 at a time, which is a better use of a kritzkrieg uber. Combine this with the fact that mediguns charge really really fast in MvM setup phase, and this brings you to the very effective strategy of kritzing a sco-res demoman before the start of the wave. Each crit sticky does 353 damage, so that's 4,942 damage off the tank as soon as it enters the field. That's not counting damage upgrades.

During the wave, though, the best kritzkrieg option is probably a soldier with a fully upgraded Beggar's Bazooka. With perfect timing you can deal multiple volleys of 10 crit rockets each. That's a total of 2,700 damage per volley (again ignoring damage upgrades). A fully upgraded kritzkrieg uber lasts 14 seconds. Say you hit the uber perfectly; with fully upgraded reload and firing times and clip... well, that's certainly a ton of rockets. Maybe even four volleys. The wiki doesn't give base activation and reload times so I can't really tell. This would be a good thing to make science about, or at least a good reason to pop that kritz canteen.

Things get more complicated and maybe counterintuitive when it comes down to the engineer. Let's say you focus 100% on the tank. Your options are:

1. Wack the sentry with your wrench while your sentries attack it.
   • 170 dps from your sentry guns (level 3 firing speed)
   • 67 dps from your sentry missiles (assuming firing speed also affects missile firing speed)
   • 288 wrench's dps (level 4 wrench attack speed)
   • Total while the sentry is active: 525 damage per second for those 9.3 seconds.
   • After 9.3 seconds (assuming you don't want to switch back to taking care of the remainder of the bots) you can simply destroy your sentry, build another one and use a building upgrade canteen. All of these actions are as fast as you are, so let's say this takes you 2 second (and $50) every 9.3 seconds. That means your sentry is only active 82% of the time (9.3/9.3+2), which brings the sentry dps down to a combined 194 dps ((170+67)*.82).
   • Your wrench dps also goes down, as you can't keep wrenching while you do this. Say you need to take an additional second to get back to the tank and wrenching. That's means you are only wrenching 73% of the time (8.3/9.3+2), so that's only 210 dps.
   • Total: 404 dps.
   • 63 dps from your minisentry (I usually don't bother but... I also assume minisentries also get bonuses from firing rate)
   • A minisentry lasts you 19 seconds (150 bullets/7.9 bullets/sec) and then needs three seconds to be replaced (let's say you're doing a perfect job out of this). So it's only active 86% of the time. So your minisentry dps reduces to 54.
   • Grand total: 458 dps.
2. Wrangle your sentry:
   • 340 dps from your sentry guns (level 3 firing speed)
   • 74 dps from your sentry missiles (the fire rate increase from wrangling is currently unkown, let's estimate 10%)
   • 54 dps from your minisentry (can't be wrangled); see above for the calculation
   • Total while wrangling: 468 damage per second
   • You fire 21.3 bullets per second, depleting your 200 bullets in 9.3 seconds. Every 9.3 seconds you must take your sentry offline as you restock metal for the time the wrangler needs to go offline. So that's 3 seconds without your sentry firing every cicle.
   • You spend the first 0.67 seconds switching to the wrench (assuming perfect reflexes), then start banging on the sentry, putting in 40 metal per hit. In 2.33 seconds you hit the sentry 4 times, putting in 160 bullets.
   • Once the wrangler does fade, your sentry deals regular 160+67 dps until you decide to wrangle it again. Say you only do when your sentry is fully stocked on bullets again. Every strike of the wrench puts 40 bullets in, but in the meantime the sentry fires 15.3 bullets. So you need to strike the sentry 2 additional times in 1.2 seconds of regular sentry fire.
   • Once you reach this point you need to switch to the wrangler and wait for it to fade in. That's an additional .67 seconds of regular sentry dps. The sentry fires 19 rounds in this period, so that's almost 10% off your wrangling time, bringing it down to 8.4 seconds.
   • This all means your sentry goes through a 13.2 seconds cycle where you do 414 dps 64% of the time, 237 dps 14% of the time and no damage 23% of the time.
   • Total without the minisentry: 298 damage per second.
   • Grand total: 352 damage per second.

Obviously every upgrade you take or don't take changes the dynamics of every number above. Wrenching the tank probably isn't so good of an idea if you haven't spent $800 in maximizing your wrench rate; you then probably want to go ahead and wrangle. You also probably also don't want to focus 100% on the tank, your sentry could for example take care of the other robots.

It is certainly worth reminding though, in general, that you do have a melee weapon, that it can be upgraded to fire very fast and that melee crits do hurt. If you're out of ammo and the nearest ammo pack is too far away, it definitely is time to bring out that bat!

(Homework: scattergun or bat, which is better?)