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SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 21, 2024 3:23 pm
by Angeldust2
MWIF calculates a combat rightly as 24,5:7, which is 3,5 and should give an exact +7 drm. But MWIF calculates a +7,143 drm.

What am I missing?
strange combat calculation.JPG
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Re: 5.0.0.1 Strange combat calculation

Posted: Thu Mar 21, 2024 4:05 pm
by rkr1958
24.5 is rounded off, in this case up, to 25 which gives the 7.143. This rounding occurs at the very end of all contributions. That is, shore bombardment, ground support

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 21, 2024 4:54 pm
by Joseignacio
I think the rounding should come after the division.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 21, 2024 6:16 pm
by rkr1958
Joseignacio wrote: Thu Mar 21, 2024 4:54 pm I think the rounding should come after the division.
11.16.5 Resolving attacks
Add up the attacking units’ (modified) combat factors, shore bombardment and ground support. Round the total to the nearest whole
number (rounding 0.5 up)
. Total the defending units’ factors in the same way.
...

Odds ratios
Compare the attacker’s total to the defender’s total and work out the basic ratio between them.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 21, 2024 9:27 pm
by Joseignacio
ODDS RATIOS

11.16.5. RESOLVING ATTACKS
(...)
Compare the attacker’s total to the defender’s total and work out the basic ratio between them.

Round the ratio to a whole number. Always round in favor of the defender. For example, 19:5 rounds to 3:1, not 4:1.

Option 40: (Chinese attack weakness) Halve the combat factors of Nationalist Chinese land units that are attacking.

Option 41: (Fractional odds) Round to a whole number in favor of the defender, then work out how far to the next odds ratio you are. Round this in favor of the defender to the next 10%.

Roll a die just before rolling the combat die (you could roll it with the combat die if you want), to see if you find the result on the lower odds or the higher odds. If you roll the percentage or less, you resolve it on the next higher odds, otherwise on the lower odds
Tonight I am very sleepy, but I think this means that you round the ratio as well, not only the attacker or defender's total. Although I thought you didnt round the totals. In this last part I was mistaken because the attacker and defender's total are not rounded before the ratio anymore in the more modern versions (WIFCE).

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 21, 2024 11:15 pm
by Courtenay
2.6. FRACTIONS
Round off a number immediately before:
  • Calculating an odds ratio; or
  • Looking the number up in a table; or
  • Comparing it to a dice roll or to a fixed value; or
  • Spending oil (see 13.5.1) or build points.
One rounds before calculating an odds ratio, thus both the attacker and defender round their combat strength. Nowhere in that list does it say anything about rounding before a combat roll. Combat ratios are not rounded. You are not comparing the ratio to a die roll. (Examples of where you do compare to a die roll are ground strikes and bottoming.)

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Sat Mar 23, 2024 11:12 am
by Joseignacio
Courtenay wrote: Thu Mar 21, 2024 11:15 pm
2.6. FRACTIONS
Round off a number immediately before:
  • Calculating an odds ratio; or
  • Looking the number up in a table; or
  • Comparing it to a dice roll or to a fixed value; or
  • Spending oil (see 13.5.1) or build points.
One rounds before calculating an odds ratio, thus both the attacker and defender round their combat strength. Nowhere in that list does it say anything about rounding before a combat roll. Combat ratios are not rounded. You are not comparing the ratio to a die roll. (Examples of where you do compare to a die roll are ground strikes and bottoming.)
Doesnt this? After all, English is not my native language but I would say they are rounding odd ratios, which comes from dividing attacker's force by defender's force.
Option 41: (Fractional odds) Round to a whole number in favor of the defender, then work out how far to the next odds ratio you are. Round this in favor of the defender to the next 10%.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Sun Mar 24, 2024 9:43 pm
by paulderynck
"immediately before" are the key words here. You can't have a ratio until it has been calculated, by which time the rounding has already happened, as the rule states.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Wed Mar 27, 2024 10:04 am
by Joseignacio
I believe the example in the RAW would make it clearer that there is a rounding afterwards (I omitted it for brevity):
Option 41: (Fractional odds) Round to a whole number in favour of the defender, then work out how far to the next odds ratio you are.
Round this in favour of the defender to the next 10%. Roll a die just before rolling the combat die (you could roll it with the combat die if you want), to see if you find the result on the lower odds or the higher odds. If you roll the percentage or less, you resolve it on the next higher odds, otherwise on the lower odds.

Example 1: 12:7 rounds to 3:2. But you have a spare 1.5 factors. This is 42.9% of the way to 2:1 (i.e. 1.5/3.5). So you get a 40% chance (i.e. a roll of 1-4) of resolving the combat at 2:1.

Example 2: 35:6 is 5.83:1 which rounds down to 5:1 but with an 80% chance of resolving the combat at 6:1.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Wed Mar 27, 2024 8:46 pm
by rkr1958
Joseignacio wrote: Wed Mar 27, 2024 10:04 am I believe the example in the RAW would make it clearer that there is a rounding afterwards (I omitted it for brevity):
Option 41: (Fractional odds) Round to a whole number in favour of the defender, then work out how far to the next odds ratio you are.
Round this in favour of the defender to the next 10%. Roll a die just before rolling the combat die (you could roll it with the combat die if you want), to see if you find the result on the lower odds or the higher odds. If you roll the percentage or less, you resolve it on the next higher odds, otherwise on the lower odds.

Example 1: 12:7 rounds to 3:2. But you have a spare 1.5 factors. This is 42.9% of the way to 2:1 (i.e. 1.5/3.5). So you get a 40% chance (i.e. a roll of 1-4) of resolving the combat at 2:1.

Example 2: 35:6 is 5.83:1 which rounds down to 5:1 but with an 80% chance of resolving the combat at 6:1.
I think the confusion, as I understand it, is there are two roundings.

For example;
(1) 48.5 attacking vs 9.5 defending factors.
(2) First rounding, 48.5 attacking rounds OFF to 49 & 9.5 defending rounds OFF to 10.
(3) Odds ratio is 49 / 10 = 4.9, which rounds DOWN to 4:1, or 4:1 with 90% of making 5:1 if playing with fractional odds.
(4) The result is different if the attacking and defending factors weren't first rounded off before calculation the odds ratio (i.e., 48.5/9.5 = 5.1 -> 5:1, or 5:1 with 10% chance of making 6:1 on the fractional.

Number (3), as I understand it, is the correct odds for both Rules as Written and Coded for WIF 7.0.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 28, 2024 12:52 am
by Joseignacio
So, I infere that in the case Angeldust is offering, the final rounding has not been made.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 28, 2024 1:30 am
by rkr1958
Joseignacio wrote: Thu Mar 28, 2024 12:52 am So, I infere that in the case Angeldust is offering, the final rounding has not been made.
Yes. He's playing with 2D10. So, his modified land combat result would be 2D10 + 7 + f. f = 0, if not playing with fractional odds or he didn't make it. Otherwise 1. So, f is your final round down.

Re: SOLVED 5.0.0.1 Strange combat calculation

Posted: Thu Mar 28, 2024 7:10 am
by Angeldust2
Exactly, as the screenshot shows, I missed the fractional roll.