Coming late to the game, I used a predefined hash lookup: 
{ # closure for qm
    
    # build lookup hash
    my $point_step   = 2000;
    my $point_max    = 18000;
    my $quota_offset = 15;
    
    my %quota;

    foreach my $p ( 1..$point_max/$point_step )
    {    
        $quota{$p} = $p + $quota_offset;
    }
    
    sub qm
    {
        my ($points, $quota) = @_;
    
        # $points-1 handles "less than but not equal"
        $points = int(($points-1)/$point_step);
        if ( exists( $quota{$points} )
         and ( $quota < $quota{$points} ) )
        {
            return $quota{$points};
        }
        else
        {
            return 15;
        }
    } # sub qm
} # closure qm

[download]
I also ran this through the test script, and it checked out OK.

I used this version of stick2, which tested OK as well: 

use constant STICK2 => [ 15, map( ($_) x 2, 15..23 ), (24) x 100 ];
sub stick2{
    my $q = STICK2->[ 1 + $_[0] / 1000 ];
    # changed to "<=", and "15"
    return $q <= $_[1] ? 15 : $q;
} # sub stick2

[download]
Update: I added kutsu's to the mix, and fixed davidrw's davidrw_2 entry.

Here are the results: 

              Rate kutsu davidrw_2 davidrw_1 ternary op_orig   qm op_c
+mp2 stick2
kutsu      37118/s    --      -19%      -33%    -92%    -92% -94%    -
+94%   -95%
davidrw_2  45997/s   24%        --      -18%    -90%    -90% -92%    -
+93%   -94%
davidrw_1  55762/s   50%       21%        --    -88%    -88% -90%    -
+91%   -93%
ternary   463776/s 1149%      908%      732%      --     -1% -19%    -
+29%   -41%
op_orig   469008/s 1164%      920%      741%      1%      -- -18%    -
+28%   -41%
qm        571464/s 1440%     1142%      925%     23%     22%   --    -
+12%   -28%
op_cmp2   650147/s 1652%     1313%     1066%     40%     39%  14%     
+ --   -18%
stick2    788323/s 2024%     1614%     1314%     70%     68%  38%     
+21%     --

[download]
While qm isn't quite as fast as op_cmp2, it will scale better for more breakpoints.

If the OP can maintain stick2, I'd go with that. However, it might be unmaintainable by Common Folk.

-QM
--
Quantum Mechanics: The dreams stuff is made of

In reply to Re: alternatives to if and series of elsif by QM
in thread alternatives to if and series of elsif by kiat

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