Sql-server – Extended Events to find Blocking and Deadlocking

Presuming your system is actually experiencing a high number of deadlocks, you could use the following query to see exactly how many actual deadlocks your server is experiencing during the next "x" amount of time:

DECLARE @startval BIGINT;
DECLARE @endval BIGINT;

SELECT @startval = pc.cntr_value
FROM sys.dm_os_performance_counters pc
WHERE pc.counter_name LIKE '%deadlock%'
    AND pc.instance_name = '_total';

-- 00:01:00 is 1 minute
-- adjust this to whatever period of time you like
WAITFOR DELAY '00:01:00';

SELECT @endval = pc.cntr_value
FROM sys.dm_os_performance_counters pc
WHERE pc.counter_name LIKE '%deadlock%'
    AND pc.instance_name = '_total';


SELECT DeadlocksOverPeriod = @endval - @startval;

I'm going to say you are getting all the extra fields because you picked a template when you built your event session (or used the wizard). If you only want certain fields then go uncheck what you don't want. However, there will be some event level info that will always be there, what is shown under the "Event Fields" for each event are their by default and cannot be removed.

Default event for "sql_statement_completed" only captures this, after I checked the global field for client application name: