The MMV gained 70 ELO over its predecessor but made a name for itself as tactical monster because it often could solve deep combinations strewing with mates in 7 or 8 moves while only doing 500-600 nodes a second on a 5 Mhz 6502 processor.
That's was quite new in those early days.
The system is described at the Inside REBEL page, paragraph long checks.
A couple of examples, again the German WIKI is quite helpful.
1. Qf7+ Kxf7 2. gxh8N+ Ke8 3. Ng7+ Kd8 4. Nf7+ Kc7 5. Ne8+ Kc6 6. Ne5+ Kb5 7. Nc7+ Kxa5 8. Nc4++ 1-0
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