1+ platelet clumps,automated count may be affected."written on cbc report. on average how many points does above 1+ clump or 2+ clump lower platelet count with normal range 150.000--450.000?

It's moot: This is a good question and it has never been answered. The lab is doing a good job of being attentive. If the count remains within normal range, we do not have to worry about low platelets. High platelets are seldom a problem and when it is, it'll be obvious from the smear.

Hard to say,,,,: It's hard to quantity how much this affects counts as different people have different counts and even a slight clumping like a "1+" may be spread extensively and involve a lot of platelets. What's likely done is to get another specimen with anticoagulant like heparin and see if that has a vastly different count. It'd be best to see your doctor about this for more tests if this is still an issue.