"Your Mac restarted due to a problem."
System.log showed boot time as 17:19 and the last message before was 17:13 but things had been working in the five minutes before the restart.
Six log files had file dates after 17:13, but five of them had NO messages before the reboot. (The other has timestamps only in raw integer format)
So how do I look for clues to what happened between 17:13 and 17:19 ?
It's a Macbook Pro 2012 refurb still under warranty (purchased January) but the RAM and SSD were transferred from an older machine.
Shutdown Cause
code in your log and see: Shutdown cause and sleep cause numbers listed/explained anywhere? – kenorb Sep 26 '17 at 15:35