substract string from column in sql

SELECT eventname
 ,CASE 
  WHEN charindex('vs', eventname) > 0
   THEN rtrim(SUBSTRING(eventname, charindex('vs', eventname) + 3, len(eventname)))
  END Away_Team
 ,replace(replace(eventname, CASE 
    WHEN charindex('vs', eventname) > 0
     THEN rtrim(SUBSTRING(eventname, charindex('vs', eventname), len(eventname)))
    END, ''), SUBSTRING(replace(eventname, CASE 
     WHEN charindex('vs', eventname) > 0
      THEN rtrim(SUBSTRING(eventname, charindex('vs', eventname), len(eventname)))
     END, ''), 0, PatIndex('%[0-9]%', replace(eventname, CASE 
      WHEN charindex('vs', eventname) > 0
       THEN rtrim(SUBSTRING(eventname, charindex('vs', eventname), len(eventname)))
      END, '')) + 2), '') Home_Team
--SUBSTRING(replace(eventname,case when charindex('vs',eventname)>0 then 
--rtrim(SUBSTRING(eventname,charindex('vs',eventname),len(eventname))) end,''),0,PatIndex('%[0-9]%',
--replace(eventname,case when charindex('vs',eventname)>0 then 
--rtrim(SUBSTRING(eventname,charindex('vs',eventname),len(eventname))) end,''))+2)
FROM tablename

where eventname  is a column name