IPM Dead in AaA:Revised?

[Magister]

[DarthMaximus said]
I think IPM is still valid.
Simply put if you are buying 10 inf (30 ipc) per turn it is going to take your opponent at least 40 ipc to defeat you.

Right, it’s mostly about how Defender’s advantage changed from Classic to Revised. The addition of arty decreased it.
I define here Defender’s advantage as the ratio of IPC costs for attacker to be ‘equivalent’ to defender (both grind to zero with average luck). Any better for one side gets a cascading victory.

Pure infantry is still the best at pure defender.
Inf vs inf: the advantage is ~1.41 (SQRT 2) from Lanchester’s theory. Would need slightly more than 14 inf to defeat 10 inf. And this is mutual - if the other side wants to attack the 14 inf, they would need 20 inf. A mutual advantage of 2 x.

A simple mix to defeat pure inf would be Inf+Arty in equal proportions.
5 inf+5 arty (35 IPC) are exactly equal to 10 inf defending (30 IPC). Each unit hits at 2.
The defender’s advantage would be 35/30 = 1.166 x.

Actually, the optimal mix for large attacking forces would be in the proportion of 60% inf, 30% arty, 10% tanks (calculated with a detailed, mathematically quite ugly model). 6+3+1 would cost the same 35IPC.
I’ve tested on simulators, for large forces (30+15+5) this is very slightly better than 25 inf 25 arty. But 6 inf 3 arty 1 tnk is very slightly worse than 5inf 5 arty to attack 10 inf (or 5 inf 5 arty). In general, most optimization problems have a ‘flat optimum zone’ around which small variations in decision result in extremely small variations in value.

If opposed by a similar force, the 50-50-0 force would have no defender’s advantage. The two forces each would cost 35 IPC and fight the same. On defence, the 6+3+1 would be a bit superior due to the 3 firepower of tank. (Roughly like 0.5 inf more, but without its staying power).

[Imperious Leader]

60% inf, 30% arty, 10% tanks

Bravo! This is what i believe as well since the game started.

We once had a great thread called " what is the best unit in AA and why" where this was debated at length.

Jennifer as i remember also espoused this idea.  Other thought tanks were more important… but as a cost per combat attribute. that ratio is a great tool.

[Weekend Gamer]

@Magister:

[DarthMaximus said]
I think IPM is still valid.
Simply put if you are buying 10 inf (30 ipc) per turn it is going to take your opponent at least 40 ipc to defeat you.

Right, it’s mostly about how Defender’s advantage changed from Classic to Revised. The addition of arty decreased it.
I define here Defender’s advantage as the ratio of IPC costs for attacker to be ‘equivalent’ to defender (both grind to zero with average luck). Any better for one side gets a cascading victory.

Pure infantry is still the best at pure defender.
Inf vs inf: the advantage is ~1.41 (SQRT 2) from Lanchester’s theory. Would need slightly more than 14 inf to defeat 10 inf. And this is mutual - if the other side wants to attack the 14 inf, they would need 20 inf. A mutual advantage of 2 x.

A simple mix to defeat pure inf would be Inf+Arty in equal proportions.
5 inf+5 arty (35 IPC) are exactly equal to 10 inf defending (30 IPC). Each unit hits at 2.
The defender’s advantage would be 35/30 = 1.166 x.

Actually, the optimal mix for large attacking forces would be in the proportion of 60% inf, 30% arty, 10% tanks (calculated with a detailed, mathematically quite ugly model). 6+3+1 would cost the same 35IPC.
I’ve tested on simulators, for large forces (30+15+5) this is very slightly better than 25 inf 25 arty. But 6 inf 3 arty 1 tnk is very slightly worse than 5inf 5 arty to attack 10 inf (or 5 inf 5 arty). In general, most optimization problems have a ‘flat optimum zone’ around which small variations in decision result in extremely small variations in value.

If opposed by a similar force, the 50-50-0 force would have no defender’s advantage. The two forces each would cost 35 IPC and fight the same. On defence, the 6+3+1 would be a bit superior due to the 3 firepower of tank. (Roughly like 0.5 inf more, but without its staying power).

This has been posted before in one form or another.  This argument only works in a vacuum, however, where you can assume the attacker will be facing the exact same defenders in any situation and it is only a question of which mix of attackers to bring to the battle.  However, this analysis completely overlooks (or cannot effectively take into account) the blitzing ability of tanks!!!  The fact that tanks purchased the turn AFTER the infantry stack leaves Germany, for example, can still participate in an assault on Moscow makes the comparison particularly difficult.  In other words, it’s not a question of x amount of artillery/infantry vs. x amount of tanks/infantry, but x amount of artillery/infantry vs. x + y amount of tanks/infantry.  In addition, the defender mix is different because, whereas tanks take two turns to reach Moscow, infantry and artillery take four, so that the stack in Russia faced by the tank stack is TWO TURNS SMALLER IN BUILDS than the stack in Russia faced by the infantry/artillery stack, which arrives two turns later.

Thus, while ratios are interesting, I think their application in a real game setting is very limited, for the reasons mentioned above and others.

[DarthMaximus]

This was a post I made last year on the subject.
The 3:1:1, 4:1:1 was what would give you one of the best offensive AND defensive stack regardless of what your opponent attacks with.

Inf to Rt in a 2:1 ratio also did very well.

And just to be clear, I was looking for the best offensive AND defensive stack.  While one grouping maybe scored high on offense maybe it sucked on def and vice versa.  Sure, 20 inf is great on Def, but it is terrible to attack with.

Anyway here some of what I did:

_Okay, I ran some analysis and I used a LL system for hits (and simplicity), both attacker and defender hit on 3 and above.

Also I used 60 IPC for total IPC to spend b/c it is easily divisible by 3, 4, and 5 and allows enough units for a couple rds of battle but not too many.

I did three groupings:
#1 -  Inf/Rt/Arm
#2 -  Inf/Rt
#3 -  Inf/Arm

And tried to find the optimum buy for each grouping.
For #1, I started with 20 inf (60) then moved down in the following increments:
20/0/0
17/1/1
14/2/2
11/3/3
8/4/4
5/5/5
2/6/6

And I had each category attack all the other categories.  So for example, I did 20 inf attack 20 inf, then 20 inf attack 17/1/1, then 20 inf attack 14/2/2…etc.  then I did the same for 17/1/1 and 14/2/2…etc.

The combo that did the most damage to the most categories was the grouping of:  11/3/3.
It did the most damgae but tied with the 5/5/5 in the category of attacking 20 inf and 17/1/1.  Both left 8 inf and 7/1/1 behind in each respective category.
but the 11/3/3 eeked out slight wins in the other 5 categories for this group.

Now for the Inf/Rt groupings using the same method I tried:

20/0/0
16/3/0
12/6/0
8/9/0
4/12/0
0/15/0

And here I came out with both the 12/6/0 and 8/9/0 grouping each winning 3 categories, with the 12/6/0 doing the most damage (or taking with the most units) against 20/0/0, 12/6/0, and 0/15/0 and the 8/9/0 grouping doing better against 16/3/0, 8/9/0, and 4/12/0.

Now for the Inf/Arm groupings I used:
20/0/0
15/0/3
10/0/6
5/0/9
0/0/12

And this was pretty clear cut as the 10/0/6 grouping did slightly more damage to each category.

Now finally I took the best from each category to squared off, so I had:

11/3/3
12/6/0
8/9/0
10/0/6

And did the same thing and found that:
The 11/3/3 won 2 and tied in 1
The 12/6/0 tied in 2
The 8/9/0 tied in 1
The 10/0/6 performed the weakest against the others.

So what does this all mean?

I think certainly in could be used to back up the idea of keeping the 3/1/1 to 4/1/1 ratio for land units as both being good offensively to take on almost any style of army and being pretty good on defense too.
Although, the mostly inf breakdowns whether it was 20/0/0, 17/1/1, or another mix with a high % of Inf dominated the defensive aspect.  You really can beat Inf for defense at the cost of 3 IPC.

I was kind of surprised by the 8/9/0 one, but I guess it makes sense since you instantly double the power of inf, but I still think the 1-1 is not the way to go, but the 12/6/0 also did pretty good.  I’ve never really given rt a fair chance but I may consider it more in the future if I don’t need the rapid movement.  Maybe load up on rt in the early rds and save armor for the mid to late rds when you may need quick movement._

And I’ll agree with Gamer that the ratios are troublesome at best to really put into real game play, esp when dealing with ftrs/boms already on the board, not to mention all the other units each side starts with.

[Magister]

Interesting experiments !
Now my 10% for tanks come from their value in a SINGLE battle - that is, they do not need a matching inf to fire at 3, whereas an ‘excess’ arty fires at 2.
Of course the speed-2 of tanks helps. Not within each ONE battle but by giving more CHOICE among battle positions.
Even speed-1 inf+arty can have choice (e.g. a Novosibirsk position projects dead zones to Yakut, Sinkiang and Kazakh).

Speed 2 of tanks in traveling from home factories allows doing what I call the ‘Cumulative Charge’ effect. For some turns, they produce slow troops, then switch to tanks only. 2-3 turns away, they arrive simultaneously on the front, overwhelming enemy or making them retreat. But after the advance a similar-sized ‘hollow’ ensues.
Usually Germany does it, but Japan can too - factories in Asia don’t HAVE to build tanks only. They can switch according to similar tactical needs.

[Guest]

Back to straight IPM…

One of the biggest things that detracts from a straight IPM is not just the extra DISTANCE to Moscow, but the extra German territories to DEFEND.

In Classic you have 4 territories to hold:  Western, Germany, Southern, and Eastern, and you have nearly all of Germany’s IPC’s secured.  In Revised, to hold the same geography, you have to hold SIX territories instead of 4.  And you only get an economic boost of $5 in order to accomplish it.

That forces Germany into a trade mentality instead of the more static IPM of Classic.  Adding that fluidity to the Russian Front instead of the knock-down drag out stack versus stack of Eastern/Karelia makes for a VERY different game, and a much greater reliance on German AND Russian offensive power.  Fine tuning the balance of punch forces becomes the key to victory… preserving air power, the right combination of ART/ARM with your INF…

INF is still probably the single most important unit in Europe, but gone are the days of it being the PREDOMINANT unit in Europe.

And as that “trade” mentality settles in to a Axis Classic player as they change to revised, their is one other massive change that a German player has to realize…  German Navy is no longer a suicide force that you hope takes enemy with you as you die, it is now a key element to your economic and strategic advances in Europe.

36 IPC buy is no longer an automatic 12 INF.  It MAY be.  But more often than not it will be a MIXED buy to include other units:  ground air and even the occasional NAVAL buy.

And for that reason, I view Revised as being a hell of a lot more fun, because even after 48 games on here, there is still something totally new in every single game.

[Jennifer]

IPM isn’t the same in revised as classic.  IPM in revised still makes you think about what route you want to take, how to coordinate with allies, etc.

In classic, you just pushed for Karelia then game over.  You either got it before Berlin fell, or you lost E. Europe.  Boring game after you do that a few dozen times.

[cyan]

i think ipm is dead for the most part.  when i’m russia i buy logisticlly ( not based on a ratio)  so i usally  hve impulses of infrantry and tank waves. when i’m germany i buy ipm for teh most part. when i’m uk or america i buy  to fill the trns so 1 inf, 1 art.  to maximaze timing to strick germany. when i’m japan i act like russia but more tanks cause longer  support lines.

[Weekend Gamer]

@ncscswitch:

Back to straight IPM…

One of the biggest things that detracts from a straight IPM is not just the extra DISTANCE to Moscow, but the extra German territories to DEFEND.

In Classic you have 4 territories to hold:  Western, Germany, Southern, and Eastern, and you have nearly all of Germany’s IPC’s secured.  In Revised, to hold the same geography, you have to hold SIX territories instead of 4.  And you only get an economic boost of $5 in order to accomplish it.

That forces Germany into a trade mentality instead of the more static IPM of Classic.  Adding that fluidity to the Russian Front instead of the knock-down drag out stack versus stack of Eastern/Karelia makes for a VERY different game, and a much greater reliance on German AND Russian offensive power.  Fine tuning the balance of punch forces becomes the key to victory… preserving air power, the right combination of ART/ARM with your INF…

INF is still probably the single most important unit in Europe, but gone are the days of it being the PREDOMINANT unit in Europe.

And as that “trade” mentality settles in to a Axis Classic player as they change to revised, their is one other massive change that a German player has to realize…  German Navy is no longer a suicide force that you hope takes enemy with you as you die, it is now a key element to your economic and strategic advances in Europe.

36 IPC buy is no longer an automatic 12 INF.  It MAY be.  But more often than not it will be a MIXED buy to include other units:  ground air and even the occasional NAVAL buy.

And for that reason, I view Revised as being a hell of a lot more fun, because even after 48 games on here, there is still something totally new in every single game.

I basically agree with everything you said, Switch.  Nicely put.

[Weekend Gamer]

@Jennifer:

IPM isn’t the same in revised as classic.  IPM in revised still makes you think about what route you want to take, how to coordinate with allies, etc.

In classic, you just pushed for Karelia then game over.  You either got it before Berlin fell, or you lost E. Europe.  Boring game after you do that a few dozen times.

Against a good Allied player, you are correct, Jen.  However, I played a game of Classic against a friend who kept buying tanks as Russia and, guess what, I took and HELD Ukraine.  And THAT was game over.  :-D

[Jennifer]

I have a bone to pick with classic.  :P

Namely, most veteran players started game play at Russia Round 2 with the game set up already.  That’s how formulaic the first round was in that game!  In Revised there’s quite a few different permutations of strategies for round 1.

[axis_roll]

@Jennifer:

I have a bone to pick with classic.  :P

Namely, most veteran players started game play at Russia Round 2 with the game set up already.  That’s how formulaic the first round was in that game!  In Revised there’s quite a few different permutations of strategies for round 1.

This is funny and sad at the same point.

We found that if certain round 1 key battles went awry (for the axis moreso than the allies) that the games outcome was pretty much set then.  Just go through the motions.

Not alot of fun… PERIOD.

We toyed with having a standard Round 2 set-up we thought was fair and just starting there.  I can not remember if we ever did that, but I KNOW we discussed it.

[Jennifer]

Oh, we pretty much had one.  It was based on most common out comes with Germany holding Egypt and Caucasus, Japan in China and India.

Of course we based ours off a Restricted Russia so the combined Kwang-Bang was moot.