Possible Bug: Avg Mana

[PoogeFactory]

Please forgive me if this post is in the wrong place or if this has already been noted; I love the deckbuilder on this site, but I've never posted before.

It appears that there's a slight issue with the average mana cost display for decks. Several times I've had the display show one value on the "Overview" tab (to the right, beneath the total $ cost), then a different value on the "Details" tab (top left, above the graph, where it says "Mana Curve"), and then a different value at the bottom of the "Details" tab (the avg shown at the very bottom between total cards and total cost). After doing the math manually, I've found that the value on the bottom of the "Details" tab tends to be correct.

In case it helps, I linked a deck I was working on recently, that produces the issue. The actual average is exactly 2.6 (no rounding). However it shows up as 2.58 on the "Overview" tab, as 2.61 above the graph on the "Details" tab, and (accurately) as 2.6 at the very bottom of the "Details" tab. I thought one possible factor could be that several of my decks have mana cost overrides on a few cards, but if one of the displayed averages wasn't taking the overrides into effect, the numbers would be even more skewed then they are.

Thanks for your time and also for this site.

https://deckstats.net/decks/64561/855577-swolbriar

[Nils]

Thank you for reporting this, good catch. I am looking into this right now but I actually arrive at 2.61 being the correct average. I only get 2.6 if I include the commander. Do you think the commander should be included in the calculation?

[PoogeFactory]

Yes, I counted my commander... but whether or not I should count the commander is not something I considered. Thinking about it now, I could see a valid argument for both ways, but in my opinion, I'd say yes. Not all commanders are cast several times (some combo immediately, and others are indestructible) and some are played with graveyard recursion in mind. Thus it's casting cost may never change. And since it gets cast like any other spell, I would argue that yes, it should be included.

Edit: used the wrong words. changed the words

[Nils]

Thanks, I am looking into this now.

[WWolfe]

I looked at this with my Sliver deck out of curiosity and it's doing the same thing. Says 2.80 average, when I do it I come up with 2.75 without the commander and 2.79 with the commander.

[Nils]

@WWolfe that's strange, according to my calculations it's 2.80 when you exclude the commander and 2.84 when you include it. How do you arrive at 2.75 or 2.79? Are you excluding any cards?

[WWolfe]

Nope, not excluding any cards. Just the commander in the one number.

ETA- I must have done the math wrong somewhere, now I get 2.80 and 2.83. I did it twice and came up with that.

[Nils]

Can you double-check if you really get 2.75 without and 2.79 with the Commander? I'm pretty sure it should be 2.80 or 2.84. Just saw your edit, glad to hear we agree now With the Commander it's 2.83870... which rounds to 2.84, right?

BTW, I started a small poll on #general in Discord to see whether we should include or exclude the Commander for the avg CMC calculations and for the mana curve: https://discord.gg/hUAHUrv

[PoogeFactory]

One last point I'll make in favor of including the commander in the default calculation, is that excluding it using the <ignore_cost> override is pretty easy, giving the user an easy choice of whether or not they'd like it in. If it is excluded by default, then adding it in is a bit more work.

That said, I won't argue with democracy, so a poll is a fine solution. And by the way, thank you for addressing the issue.

[Nils]

Yes, that's a good point. The results of the poll were also clearly in favor of adding the commander, so I will change that with the next update.

[PoogeFactory]

Sounds great; thanks for this.

[Nils]

Now fixed: https://deckstats.net/forum/index.php/topic,56039.msg164969.html

[PoogeFactory]

I checked on a few decks; the numbers are accurate, and consistent across the pages. And on a side note, the UI definitely looks improved since the update. Thanks again.

[Nils]

I'm happy to hear that! Thanks for letting me know.