Winning with only a king

In this game I sacrificed my last non king piece and then won the game.

It just occurred to me that if Black's time expires and White cannot construct a checkmate (having only a single piece, or two knights, or White is stalemated irrespective of Black's move), the result should be a draw.

EDIT: Oh, good, it seems to work:

@acgusta2 #1
Nice. Thumbs up.

But that's wrong! It's possible to construct a checkmate from that position!

@Vempele Agreed. Hm. @acgusta2 But you did it unnecessarily.

A lone knight needs three helper pieces (and not all combinations work).

Two knights can mate against a bishop, knight, or pawn, but not against any number of rooks or queens.

A bishop can mate against two bishops that are opposite to its color, or an opposite-colored bishop and a rook's pawn that would promote to the wrong color. There are also patterns with the king not in the corner that require more pieces.

A queen can mate against a lone rook (or pawn) or like a bishop of a color of her choosing.

A rook can mate by back rank or its vertical analogue.

Oh wow, yes White can mate as described in #6. Oops.

For example, if the king times out, in cases like this the horde should win with a single pawn:
lichess.org/editor/k7/ppP5/brp5/8/8/8/8/8_b_-_-

@Toadofsky

I've created a study showing how you could help white win no matter what white promotes to

@acgusta2 Thanks, for now I'm focusing on ensuring 2-man, 3-man, 4-man, and 5-man endgames evaluate properly (in terms of whether a mate can be constructed), then I'll tackle the larger issue.
github.com/ddugovic/scalachess/commits/horde_fortress