How to optimize a MDX aggregation functions containing "Exists"?

Question

I have the following calculated measure:
sum(([D Player].[Player Name].[All],
exists([D Match].[Match Id].children,([D Player].[Player Name].currentmember,[Measures].[In Time]),"F Player In Match Stat" ))
,[Measures].[Goals])
Analyzing this calculated measure (the one with "nonempty") in MDX Studio shows "Function
'Exists' was used inside aggregation function - this disables block computation mode".
Mosha Pasumansky spoke about this in one of his posts titled "Optimizing
MDX aggregation functions" where he explains how to optimize MDX aggregation functions containing "Filter",
"NonEmpty", and "Union", but he said he didn't have time to write about Exists, CrossJoin, Descendants, or EXISTING (he posted this in Oct. 2008 and the busy man didn't have time since that date :P )... so anyone knows an article that continues
on what Mosha miss or forgot? how to optimize a MDX aggregation function containing "Exists"? what can I do to achieve the same as this calculated measure but in block mode not cell-by-cell mode ?

Answer 1

Sorry for the late replay.
I didn't check if your last proposed solution is faster or not, but I'm sorry to say that it gave the wrong result, look at this:
Player Name
Players Team
Goals Player Scored with Team
A
Team's Goals in Player's Played Matches
Lionel Messi
Argentina
28
28
110
Lionel Messi
Barcelona
341
330
978
The correct result should be like the green column. The last proposed solution in the red column.
If you look at the query in my first post you will find that the intention is to find the total number of goals a team scored in all matches a player participated in. So in the above example Messi scored 28 goals for Argentina (before the last world cup:)
)  when the whole Argentinian team scored 110 goals (including Messi's goals) in those matches that Messi played even one minute in.