L.A. Times Problem No. 251 by C.G. Watney, England. Good Companion Folder, May, 1920. White mates in two.
FEN 8/8/8/6QB/6NK/3NB3/5pkp/6b1 w - - 0 1
Key: B-B4/Bf4. Shows four self-blocks by two promoted black pawns; not a record, as five have been done by this force and six seem to be a possibility.
L.A. Times Problem No. 252 by S. Mlotkowski, Camden, New Jersey. From the Bethlehem Globe Times, March, 1930. White mates in three.
FEN 8/8/1p6/1P1pkPP1/1B4P1/6PN/3PK1B1/8 w - - 0 1
Key: 1. P-Q3/d3
If P-Q5; 2. K-B3, etc. If K-Q5; 2. N-N, etc.