Are the olympique mathematique belge semi finals harder than the finals
Executive summary
Official OMB materials and archival summaries state that the demi‑finale’s questions are “of the same type” as earlier rounds but “present a degree of difficulty slightly higher” than the éliminatoire; finals are described elsewhere as having fewer open questions requiring full justification (4–5 problems) [1] [2]. Available sources do not give a direct, quantitative difficulty comparison between demi‑finales and finales across editions [3].
1. What the organisers say: demi‑finales are a notch harder
The Société Belge des Professeurs de Mathématique (SBPMef) explicitly describes the demi‑finale as using the same question formats (mostly multiple choice and some integer‑answer items) as the éliminatoires but with “a degree of difficulty slightly higher” [1]. That phrasing implies the demi‑finale is intended to be more selective than the first round, not necessarily the single hardest stage of the competition [1].
2. What the final looks like: fewer problems, deeper answers
Descriptions of the OMB final emphasise a different format: instead of many short items, the final typically gives 4 or 5 long problems for which “answers and reasoning must be thoroughly explained” [2]. That change in format shifts the challenge from breadth to depth and exposition, which many contestants and coaches treat as a qualitatively tougher test of mathematical maturity [2].
3. Different axes of difficulty: quantity vs. depth
Because demi‑finales use many multiple‑choice and short numerical questions (as noted by SBPMef) while finals use a small number of full‑solution problems (as noted by the Wikipedia summary), the two rounds test different skills: speed and accuracy over many items in the demi‑finale; problem modelling, creativity and written proof in the final [1] [2]. Which is “harder” depends on whether one weighs breadth and time pressure more than depth and proof‑writing [1] [2].
4. Selection pressure and statistics: semi‑final cuts are steep
The Wikipédia entry reports that about 10% of top scorers from the éliminatoire are selected to the demi‑finale, indicating strong culling early in the process; the demi‑finale therefore functions as a high‑filter round to pick finalists [2]. Regional and historical archives show explicit qualification thresholds and large initial participation, confirming that the semi‑final stage is a key sieve [4] [5].
5. Evidence from problem archives: comparisons are possible but limited
Complete question collections exist for recent years (recueil 2019–2022 and problem booklets) which would allow direct side‑by‑side comparisons of problem difficulty by type and year, but available sources here do not present a systematic difficulty metric across demi‑finales and finals [3] [6]. Therefore any claim that one stage is categorically harder for all years is not supported in the provided reporting [3].
6. Practical implications for competitors and coaches
Given the structural differences, training differs by stage: practice on many short, fast items prepares students for the demi‑finale’s multiple‑choice and numerical pressures; targeted problem‑solving and proof practice prepares for the final’s few, deep questions [1] [2]. The SBPMef runs selection and preparation programmes and invites top participants to training weekends, underscoring that finalists are expected to handle the depth of final problems [7].
7. Where sources disagree or leave gaps
Sources consistently describe formats but do not quantify “hardness” across stages. SBPMef says demi‑finale difficulty is “slightly higher” than éliminatoires [1], while other summaries focus on the final’s format without stating whether final problems are systematically harder than demi‑final questions [2]. A definitive, data‑driven comparison (e.g., solving rates, score distributions, cross‑year difficulty indices) is not present in the materials supplied [3].
8. Bottom line for the original question
Official descriptions show the demi‑finale is harder than the elimination round in format and targeted difficulty [1], while the final shifts to fewer, proof‑based problems that demand deeper argumentation [2]. Which stage is “harder” depends on whether you judge difficulty by the relative increase in technical challenge across many short items (demi‑finale) or by the depth and proof requirements of a small set of final problems (final) — a distinction reflected in official SBPMef material and competition summaries [1] [2]. Available sources do not supply a single metric declaring one stage categorically harder across all years [3].