Game of Boyles

"Vladimirov's thunderbolt of 1987", as mentioned by Holt, is an actual chess move. It is ranked as the 4th best move of all time by chess.com.

In the initial release, the scene where Lyndon hugs Pappy showed Pappy's missing left hand as a green screen glove worn by actor Hal Alpert that should have been digitally removed. This mistake was corrected when the effect was later completed for streaming and repeat viewings. The green screen glove is also seen later, when Lyndon is talking to Pappy in Pappy's office. This was not corrected.

References Harriet the Spy (1996)