declare @AccountsOpen table(EmployeeID int, AccountID int)

declare @AccountsClosed table(EmployeeID int, AccountID int)

insert into @AccountsOpen values(1, 101),(2,201),(3,301),(4,401)

insert into @AccountsClosed values(1, 101),(1,201),(3,401)

Here Two accounts(101,201) colsed by  employee1
     One account(401) is closed by employee3
     301 is not yet closed so employee3 gets another point
     
    As per my understanding, result should be as follows:
    
    employeeid    TotalPoints
    1		      2
    3		      2
  
SELECT employeeid, count(points) 'totalPoints'
FROM (SELECT employeeid, 1 points
		FROM @AccountsOpen
		WHERE AccountID NOT IN (select AccountID from @AccountsClosed)

		UNION all
		
		select EmployeeID, 1 Points 
		from @AccountsClosed 

	  ) t
GROUP BY employeeid