Movement speed increases are additive, not multiplicitive

Someone in my guild posted the following:

normal run = 100, normal 60% mount = 160, mount with just carrot = 163, mount with just glove enchant = 162, mount with both glove and carrot = 165

This indicates multiple movement increase effects are additive, but the notes for patch 6.0.2 indicate the following:

Previously, multiple movement speed modifiers on you were multiplicative, meaning that if you had two different +25% movement speed bonuses, they resulted in a total movement speed of 56% (1.25*1.25 = 1.56).
Movement speed bonuses have been changed to be additive. The previous example with two different +25% movement speed bonuses would result in a total movement speed of +50%. The logic governing which bonuses stack with others has been simplified as well.

The glove + carrot should give the rider 1.6*1.02*1.03=1.681, which is greater than the observed value of 1.65.

Another person in my guild tried it with spurs attached, which should give a 4% increase. When wearing gloves, spurs, and the carrot, they observe a speed of 209% instead of 2*1.02*1.03*1.04=2.185(218.5%)

Ok, so this is like the 3rd time I’ve seen someone post a patch note from like 5 expansions later with the wording “Previously . . .” and assume that “previously” applies ALL THE WAY back to Vanilla.

AFAIK, the fastest mount speed possible was +109%… additive. Now I don’t have the time now, but I’m certain finding proof of this is easy.

But seriously. Stop using these decade later patch notes that say “previously” and thinking they applied in 2005.

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If you visit the WoWpedia page for Speed, and look at the history (specifically the versions that were active during vanilla), you will see this RE: mount speed increase stacking:

The fastest sustainable land speed possible in the game seems to consist of an epic mount (100% speed increase) in conjunction with the Carrot on a Stick (3% mounted speed increase), Riding Skill enchant (2% mounted speed increase), and Mithril Spurs (4% mounted speed increase), for a total of 218.5% of the speed of an unmodified character (since 2.00 * 1.03 * 1.02 * 1.04 = 2.185248).

There was an edit to the Speed page during BC that changed it to show mount speed increases as additive, but that was quickly reverted due to bad evidence. You can visit the discussion page for Speed to see the evidence presented for stacking mount speed increases is multiplicative (however the screenshots are no longer available).

So that’s my evidence for it not being correct in Classic, and that those specific patch notes DID apply in 2005, as opposed to your “Oh you’re wrong but I don’t have time to find any actual evidence supporting me even though it should be ‘easy’ to find…”

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First of all, the point of my comment was to point out bad argumentation not prove the bug, so not having the time find sources when I made that comment was not my purpose.

I still stand by my comment that using a patch note 10-15 years later that says “previously” as a source is not a legitimate argument.

You found better information as needed.

All archived discussion I can find about mount speed, carrot on a stick, and mithril spurs state they were reported as multiplicative values by the addons that measured them then. Could be AddOns using the wrong formula, or it could be true.

Regardless, this certainly meets the threshold to be taken in as a supported ticket and potential bug in their system.

Make a macro with:

/script x=GetUnitSpeed("player") DEFAULT_CHAT_FRAME:AddMessage(format("Speed: %d yds/sec, %.1f kph, %.1f mph, %d%% normal run speed",x,x*3600/1093.6133,x*45/22,x/7*100))

Start moving and press it. It will show your speed. You can easily see if they are additive or multiplicative this way.

You are attacking the source, and not actually offering any evidence against my description from the primary source. Simply put, the idea that some arbitrary amount of time renders my evidence irrelevant, without any evidence to the contrary from you or anyone else, is one hell of a logical fallacy.

Which I did not need to do, you needed to show evidence that runs counter to the claim I made. Which, as you found out (even though you characterized it as ‘easy’) is impossible as it (as stated in the patch notes) never changed until that point in time.

This is a real possibility. Before 3.0.1, which introduced the GetUnitSpeed function, the way to determine unit speed was to take the square root of the quadrance between a starting and an ending point over some time interval. Viewing the source for a version of MonkeySpeed from before 3.0.1, the authors noted that z-distances, non-square coordinates, and non-uniform coordinate scales present challenges that they appear to have overcome.
It would be interesting to find some data from around this time comparing the custom implementation of the “instantaneous” speed meter in MonkeySpeed to the implementation provided by Blizzard, but I was unable to find anything like that.

The guild mate I quoted in the first part of my post used the macro

/run print(GetUnitSpeed("player")/7*100)

while equipping items that provide movement speed increases to record his actual movement speed in various states.

A mechanic can change from state A to state B to state C, D, E, and maybe 10-15 years later, a patch note says “previously” referring to state E, but you think it refers all the way back to state A.

The onus is on the bug reporter to prove it is a bug. It’s completely not a fallacy to dismiss evidence 10-15 years after the fact without additional proof proving the continuity of whatever “previously” was referring to.

I don’t really need to do anything. This is why the Fifth Amendment is a thing. You can remain silent all day, bud. It’s on the prosecution to prove whatever their case is.

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But that DID NOT HAPPEN IN THIS CASE. You rejected my valid evidence from the primary source immediately and out-of-hand because of something that you imagine could have happen. It would have been one thing to present actual evidence to the contrary, or even simply asked “Are you sure it was this way in Vanilla?” but you instead chose to act in a logically fallacious and intellectually dishonest way.

I provided evidence. You rejected that evidence in an intellectually dishonest way. Again, there are ways you could have raised your objections without it being dishonest.

You do need to provide evidence when you make the claim that my evidence is faulty or deficient. And you are well aware this is not a damn court of law and the levels of evidence are vastly different.

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In TBC a riding crop was added, and no other movement speed items worked with it. It was a flat 10% speed, which would indicate that vanilla was not multiplicative, but additive.

Also, you call people on logical fallicies but you presented your case on one.

If you look at the section of the 6.0.2 patch notes dealing with movement speed, they touch on the fact that a lot of movement speed increases did not stack with others. After the change in 6.0.2, that was simplified and they let a lot more stack.

Under the old set-up, each movement speed bonus would become more powerful when combined with another, so we would limit what can stack with what, and prevent certain abilities from being used when another one is already in effect.

This does not follow any logical path. The max you could get in vanilla was 218.5%, with the crop you would obtain 220% (2*1.1=2.2). And again, I have presented additional evidence FROM VANILLA showing these specific mount speed increases were multiplicative.

In fact, the wiki has this information for Riding Crop:

It gives approximately 1.5% more mounted speed than the Riding Skill/Mithril Spurs/Carrot on a Stick combo (and saves two bag spots). This has been tested with visual comparison to other players with varying degrees of speed enhancing items as well as with speed measuring in-game mods.

And which fallacy do you believe I used, exactly?

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