A checkpoint is part of training

TD7’s policy checkpoint is more than a training-recovery file: it is a policy copy selected through training-time assessment. The current learner, data-collection policy, and reported policy may differ.

The source discusses selecting candidates through minimum assessment return. Let CcC_c be the saved score and mkm_k the candidate’s minimum after k episodes. Additional episodes cannot increase that minimum:

min⁡(R1,…,Rk,Rk+1)≤mk.\min(R_1,\ldots,R_k,R_{k+1})\leq m_k.

A candidate already below the threshold can be rejected early. Acceptance still requires the intended assessment length and implementation-specific tie rule; a few favorable trials are insufficient.

Interpreting the minimum

Minimum return favors consistency in the observed sample, but depends on episode count, randomness, and extremes. It is not automatically a CVaR estimator or a guarantee of future worst-case performance. Assessment scheduling is therefore part of the algorithm.

Record Role
Current actor/critic/encoder Optimization and recovery
Saved policy plus required representation Consistent action generation
Assessment experience Candidate selection
Independent evaluation Performance and uncertainty reporting

Save dependent embeddings, normalization, and configuration with the actor. Selection episodes consume budget and must not be reused as independent final-test evidence.

Reproduction records

Record acceptance criteria, maximum assessment length, early rejection, exploration noise, and when the candidate is frozen. Compare current and checkpoint policy curves so selection effects are not attributed entirely to representation learning.

Related reading: TD7/SALE, statistics and tuning, and evaluation.

Selected references from the source notes