The default behaviour, or if this value is set to 0
is to mark
a build as failed immediately if checking out from the SCM system fails.
Setting this to a higher number means Jenkins will attempt to check out from
the SCM system that many times, with a ten-second delay between retries.
If the final attempt also fails, then the build will be marked as failed, and
execution will stop.
As plugins can contribute different Source Code Management implementations, it's up to each individual implementation to define what constitutes a checkout failure.
If this option is not checked, then the system-wide default value from the Configure System screen will be used.