What should a work supervisor put in a recommendation letter for someone applying to statistics PhD programs?
The readers of such letters will normally be looking for predictions of success in the academic program and thereafter. The past is less important (what you have already done) unless it supports that prediction of success.
If the letter writer understands that, and they are supportive, then you should be fine. But a &quot;bald&quot; statement that &quot;I predict the success of this person.&quot; is too easy to discount. It needs to be a bit more subtle than that.