I am using blastx to blast nucleotide sequences against a custom protein database.

Here is a snippet of my output. These are all the HSPs for seq1 against subject1

I'm confused by the value of qcovhsp. Consider the first row. qlen = 141, qstart=139, and qend=2. I would think that the qcovhsp would be around 97%

(139 - 2) / 141 = .971

Why then is qcovhsp 33? In fact, scrolling through my results I don't see any qcovhsp values > 33. Does qcovhsp behave differently in blastx than it does in blastn?

FYI this was the command I used to run blast.

 blastx -task blastx \
        -db my_protein_db \
        -query my_fasta.fasta \
        -query_gencode 11 \
        -outfmt "6 qseqid sseqid qlen qstart qend sstart send pident qcovhsp qcovs qseq" \
        > output.txt