Im on record as disagreeing with cannonshop on vtols. His advice about building fast glass cannon VTOLs was 100% correct before TW, but with TW the yellow jacket, as a unit in a battletech game and not in a 1 v 1 vtol duel, is fantastic and probably the best gauss rifle unit the inner sphere can field for the battle value. I think a mantis kills a Hollander from the rear before it kills a Yellow Jacket in about 75% of games, and the Hollander is 171 BV more then the Yellow Jacket. The +4 or 5 TMM on the Yellow jacket versus +2 or 3 at most on the Hollander is just that big of a difference in team fights.
In combined arms team fights, especially with accuracy bonuses and later era weapons, an advancing VTOL going for a flank will draw hate from the whole enemy team. The side chart through armor crits are the biggest things to watch out for here. Most vtols do not have side mounted weapons, which means on the side crit table, a roll of 6-10 on the crit table kills the engine, while 11 is ammo and 12 is fuel. Through armor crits to your side happen 1/6 times, so when attacked there is a 6/36 chance of a TAC followed by a 26/36 chance that crit converts to engine/ammo/fuel. So you expect that around 8 hits to your side will kill you on standard deviation (about 2/3rds the time). I feel like you want enough armor on the side to make the enemy need that 1 in 8 to get your engine. If you feel like 2 damage is about the average cluster size, you want at least 16 armor--more once HAG and artillery shows up and becomes the dominate AA weapons. If you think there will be more LBX 1 damage pellets, then you need to mount weapons in the side arcs. Mounting weapons turns the 6-10 crit results from always hitting your engine, to only a 10+. Thus, instead of needing 8 hits to the side to kill your engine (or worse) you need 36 hits to roll an engine crit. This means you can safely mount armor and feel secure an LBX pellet wont ruin your engine, they need to get rotor hits instead.
Putting it together... Something like the royal cyrano with side AMS guns needs more armor. At only 10, you will die to raw damage at a mere 13 points. The Pinto is much better at 18 side armor, as long as you buy a cheap squad to eat a side crit 'infantry hit' you change the 6+ side crit to an 8+ crit roll needed. You can expect the pinto to live when getting hit in the side with 2 damage attacks 9 times, thanks to the infantry. This 71 armor pinto is about the bare minimum versus 2 damage shots. When HAGs and AA arty are in the Era, you see lots more 5 damage attacks so will want more armor of course.
All vtols greatly benefit from more armor with the addition to a turret. The turret eats rotor hits, so it is very valuable, but only if it survives damage. So you need 15 or so armor to the turret to make it not a potential liability. So while a pinto at 71 armor is a bare minimum versus 2 damage SRMs, you would want 86+ armor on the same vtol if it had a turret it also needed to protect.
As a final note, assuming no turret, your rotor gets hit 15/36 times. So a handy breakpoint for standard deviation armor value minimums is total rotor health * 2.4 =damage cluster you want to be safe from. This means if you are trying to guard against the 3 damage mantis strikes on a 20-30 ton vtol, well you have 5 rotor health *2.4=12. So 36 armor in any one location means you shouldnt die within standard deviation to raw damage, only to rotor or TACs (and side vulnerability means if you have nothing padding the side crits those locations will only tank 24 damage before you are crit/destroyed). So about 120 armor is the benchmark versus 3 damage groups without defensive gear/padding.
I quite like the Crane as a tough transport bird. At 112 armor and with side sponson machine guns, the 30 side armor and +5 TMM means its going to get to its target and drop the cargo under LBX flak most of the time. It can survive an AA artillery shot, but needs more armor to be good versus HAGs.
EDIT: TL;DR--mount turrets AND some tiny weapons in the side, and go for 100+ armor on the big birds.
as I said, and I'll say it again; MY experience isn't everyone's. Devian likes the flying urbie, and who am I to say he's not successful with them?
I just find that my opponents (whom are not 'Princess' in megamek) tend to be a different sort of player, and slow VTOLs end up being dead VTOLs on the second or third match we play because they stop leaning on the icebox pulseboat Clanner Assault 'mechs, and start using actual tactics.
also, my dice are unkind to me, particularly when it's something like a PSR, so I avoid situations that dictate needing to roll one unless they're truly unavoidable. People with good dice often get away with things that I, in general, can't.
Which is why I keep harping on "stop theorizing and start playing!!"
The secret to Battletech is that there are no winning formulas that work for everyone, this isn't chess, it's not checkers, there's no 'guaranteed win condition' you can gear for-you still have to be able to APPLY your ideas effectively, or they're just noise on a page.
I've never had good success with assault weight ANYTHING. if a match devolves to 'stand in one place rolling dice' I end up either getting bored and losing, or just losing on the dice rolls. Then again, I'm also a filthy attrition player, and go into matches with the expectation of losing units to gain my objectives, thus, I don't tend to overcommit on custom designs to begin with, beyond cheap modifications or if I'm testing a specific theory to breaking point (Like "can I use TSM as a sustained speed boost without cooking the pilot?")
The real test of any game theory, is when you hand your customized units over to your opponent, and take HIS army and see if your outcome matches-aka if he won, can you win using his layout? if you won, can HE beat YOU using YOUR layout?
It was THAT kind of testing that soured me on slow VTOLs- I couldn't make them win, and neither could my opponents. This wound up being true even WITH the Rotor Hit Nerf, though it did let the Yellowjacket last a couple turns longer unless someone had LRMs.
but...that's MY experience, not Devian's. Playing style, choice of opponent, dice luck, inclinations-these matter a hell of a lot more than statistical number crunching in a vacuum.
I tend to generate players who outfit to gut conventional units-because I tend to USE a lot of conventional units, and play them aggressively. Thus, my opposition tends to include a lot of LBX, cluster, LRM, and so on after about the first two or three game sessions, and infernoes-even nerfed as they are under TW, they're still good for brewing up tanks and making life...difficult...for other units.
But that's experiential, not objective, because playing victory is not something you can pre-calculate objectively.
The best you can do is a match wherein you have 40% chance of winning, and so does the other guy, and that last 20% is random chance, player skill, and externalities.
There are ways to help 'lean' that-like knowing where YOUR strengths as a player lie. I've seen guys who can win against Clan Binaries using a lance of Urbies before, and I've seen guys who can't win if you give them Wolf's Dragoons (in Clantech) against scrub militia.
WITHOUT tweaking rules or scenarios ahead of time.
For my part, slow VTOLS require cooperation between both sides to remain relevant to the outcome. A Yellowjacket in a force optimized to use it, is a force Detriment-that same force is more effective WITHOUT IT.
but that's my experience, not his, maybe not yours. YOU NEED TO FIND PLAYERS. If necessary, you need to RECRUIT players...and play. Play every weekend if you can, sometimes during the week in barracks or in your dorm, but play the game, that's how you get better. You don't get better cycling and re-cycling designs you'll never use.
