I know that the judges have quite often commented when one of the contestants has too small of a tang when the plans call for a hidden tang. I also wonder at times if there might also be a nick or grinding err on the tang just before the blade.
But I agree the show is one reality show that I really enjoy. It is amazing at some of the quality that is put out by the contestants undet the time constraints that they are under.
It is so often the actual tang design and sometimes the time constaint that makes the difference.True, if the particular pattern calls for a hidden or blind tang, no choice. But I do see some of the contestants purposefully do it even though they have the choice of a much more robust handle attachment. Also true that there are some really well made and attractive blades produced under the extremes of the skills required and time constraints of the program.
a hidden tang can and should start out almost full width with no stress risers and make a double angled shape toward the end of the tang.
In the quick sketch the circled area is where the stress often occurs so needs to be lightly radiused (as is the full length of the tang) so there is no spot for the stress to start and with the wide tang at this point going through usually a metal bolster or spacer there is plenty of strength in the bolster material to withstand the stress against the wide tang slot and as the tang narrows into the handle it is a simple matter to do the tang slot but this is not a quick process and time constraints mean the contestants often rush the tang forging and end up without the stress relief or alternatively forge the tang too narrow to speed up fitting to the handle .