Benchgen

MBPP+ — Results

RankModelScore
1o1-preview80.2
2o1-mini78.8
3qwen2-5-coder-32b-instruct77
4gemini-1-5-pro74.6
5claude-3-5-sonnet74.3
6deepseek-v2-574.1
7claude-3-opus73.3
8deepseek-v373
9gpt-4o-mini72.2
10gpt-4o72.2
11gpt-3-5-turbo69.7
12claude-3-sonnet69.3
13claude-3-haiku68.8
14gemini-1-5-flash67.5
15command-r-plus63.5
16gemini-pro61.4
17llama-3-1-8b-instruct55.6

MBPP+

1 phaseActive

EvalPlus's rigorously-tested, sanitized subset of MBPP's entry-level Python problems, using many more test cases per problem than the original benchmark.

Overview

MBPP+

Category Metric Tasks Saturation Created

Paper GitHub

Quick answer: MBPP+ is the EvalPlus framework's rigorously re-tested and sanitized version of MBPP (Mostly Basic Python Problems), narrowing the original dataset to 399 well-formed entry-level problems and dramatically expanding the test cases per problem so that superficially-passing but subtly-wrong code can no longer hide.

At a Glance

What it tests: Whether LLM-generated Python solutions to entry-level programming problems are genuinely correct across a much wider range of inputs than MBPP's original, sparser test suites checked for.

Why it matters: Like HumanEval+, MBPP+ exposed that a meaningful share of previously "passing" model solutions on MBPP were subtly wrong, and that stricter testing can reorder which models actually generate the most reliable code.

Known limitations: MBPP+'s 399-problem set is a sanitized subset of the original ~974-problem MBPP (filtering out ambiguous or malformed problems), so it is not directly comparable in raw count to the full original MBPP.

What MBPP+ Measures

EvalPlus's test-augmentation pipeline — combining LLM-based and mutation-based test-input generation — was applied to both HumanEval and MBPP. For MBPP, this involved first sanitizing the original ~974-problem dataset down to 399 well-specified problems, then generating far more test cases per problem than MBPP's original hand-written tests provided.

Across the 26 LLMs evaluated in the EvalPlus paper (including GPT-4 and ChatGPT), the stricter MBPP+ test suites reduced measured pass@k scores relative to the original MBPP and, as with HumanEval+, changed which models ranked best.

Benchmark Specifications

FieldValue
Task categoryCoding / rigorous entry-level Python synthesis
Metricpass@k on the sanitized, expanded test suite
Number of tasks399 problems (sanitized subset of MBPP)
SaturationHigh for older/frontier models on original MBPP, but meaningfully lower and more discriminating on MBPP+
Created byJiawei Liu, Chunqiu Steven Xia, Yuyao Wang, Lingming Zhang (University of Illinois Urbana-Champaign)
Source paperLiu et al. 2023
GitHubevalplus/evalplus

How MBPP+ Is Scored

Generated code is executed against the sanitized problem's expanded test suite; pass@k reports the probability that at least one of k independently-sampled generations passes every test case, following the same evaluation protocol as the original MBPP but with substantially more test coverage per problem.

State-of-the-Art Results

The EvalPlus paper found that, as with HumanEval+, MBPP+'s stricter test suites reduce measured pass@k and can change model rankings relative to the original, more permissive MBPP. See the EvalPlus leaderboard for current per-model results.

MBPP+ on Benchgen

No Benchgen results yet — be the first to run MBPP+.

MBPP+ vs Other Benchmarks

BenchmarkWhat it testsTasksSaturation
MBPP+Rigorously-tested entry-level Python problems399high
MBPPOriginal, sparser-tested entry-level Python problems974high
HumanEval+Rigorously-tested Python function synthesis164high

MBPP+ complements HumanEval+ by focusing on simpler, more entry-level problems drawn from crowd-sourced MBPP submissions rather than HumanEval's hand-authored interview-style problems, giving a second, independently-sourced rigorous-testing signal.

Run MBPP+ on Your Model

Benchgen lets teams evaluate their own model against MBPP+'s expanded, sanitized test suite, surfacing correctness gaps that the original MBPP's sparser tests would otherwise miss.

Frequently Asked Questions

What is MBPP+? MBPP+ is EvalPlus's sanitized, rigorously re-tested version of MBPP, narrowing the dataset to 399 well-formed entry-level Python problems and adding far more test cases per problem.
What does a good MBPP+ score look like? Because MBPP+'s stricter tests reduce measured pass@k relative to original MBPP, a strong MBPP+ score is one that holds up close to a model's original MBPP score rather than collapsing under stricter testing.
Who created MBPP+? MBPP+ was created by Jiawei Liu and collaborators at the University of Illinois Urbana-Champaign as part of the EvalPlus framework, published in May 2023.