Measure calculated two times in filtered visuals

[nhch]

Hi guys,

I have this simple set up, just one table with one column and a measure:

top50 = IF(CALCULATE(AVERAGE(TestTable[number]), ALLSELECTED(TestTable))<MAX(TestTable[number]), "yes", "no")

if i visualize it in a table everything goes as expected:

it also works when i add a visual filter, correctingly updating the value

but if i remove the filter (in order to have the simplest setup) and try to filter this table direct in order to show just the rows that have "yes" in the measurement it shows me the correct rows but recalculate the measurment and so i get a different value.

I don't know if this is a bug or a feature, if it's the latter how can i adjust the DAX in order to not consider the filters in that visual object but keep considering the filter in other objects? 

Thank you in advance!

[Greg_Deckler]

@nhch Well, it likely has to do with your use of ALLSELECTED, perhaps one of the more complex and esoteric functions in all of DAX in terms of exactly what it considers as "selected". Will see if I can recreate and test.

[nhch]

Thank you!
It should be pretty easy to recreate, i'm on the last version, the datamodel and the formula are pretty straight forward. Tell me if i need to upload the .pbix ^-^

[nhch]

@Greg_Deckler  i did a bit of debugging and there is, in fact, a double evaluetion of the measurement. First in order to filter the data and secondly to display the value. Validity of the forumula aside, isn't this a big performance issue? filtered measurements could run twice as fast if instead of re evalueting them pbi just memorize the values! 
here it is the log (sorry if the numbers are in italian ^-^):
First call:

Second call:

P.S.
This is how powerbi builds the query, you can see the double evaluation marked in red

Thanks ✨