diff --git a/align.c b/align.c
index 163a299..1ed42e5 100644
--- a/align.c
+++ b/align.c
@@ -143,6 +143,10 @@ static void mm_align_pair(void *km, const mm_mapopt_t *opt, int qlen, const uint
 		for (i = 0; i < qlen; ++i) fputc("ACGTN"[qseq[i]], stderr);
 		fputc('\n', stderr);
 	}
+	if (opt->flag & MM_F_SR) {
+		flag |= KSW_EZ_APPROX_MAX;
+		if (flag & KSW_EZ_EXTZ_ONLY) flag |= KSW_EZ_APPROX_DROP;
+	}
 	if (opt->flag & MM_F_SPLICE)
 		ksw_exts2_sse(km, qlen, qseq, tlen, tseq, 5, mat, opt->q, opt->e, opt->q2, opt->noncan, opt->zdrop, flag, ez);
 	else if (opt->q == opt->q2 && opt->e == opt->e2)
diff --git a/main.c b/main.c
index b574782..d0ac576 100644
--- a/main.c
+++ b/main.c
@@ -156,17 +156,19 @@ int main(int argc, char *argv[])
 				k = 19, w = 19;
 				opt.a = 1, opt.b = 9, opt.q = 16, opt.q2 = 41, opt.e = 2, opt.e2 = 1, opt.zdrop = 200;
 				opt.min_dp_max = 200;
-			} else if (strcmp(optarg, "short") == 0) {
-				k = 17, w = 7, is_hpc = 0;
+			} else if (strcmp(optarg, "short") == 0 || strcmp(optarg, "sr") == 0) {
+				k = 21, w = 11, is_hpc = 0;
+				minibatch_size = 50000000;
+				opt.flag |= MM_F_SR;
 				opt.a = 2, opt.b = 8, opt.q = 12, opt.e = 2, opt.q2 = 32, opt.e2 = 1;
 				opt.max_gap = 100;
 				opt.pri_ratio = 0.5f;
 				opt.min_cnt = 2;
 				opt.min_chain_score = 20;
-				opt.min_dp_max = 50;
-				opt.best_n = 10;
-				opt.bw = 100;
-				opt.mid_occ_frac = 1e-4f;
+				opt.min_dp_max = 40;
+				opt.best_n = 20;
+				opt.bw = 50;
+				opt.mid_occ_frac = 2e-5f;
 			} else if (strcmp(optarg, "splice") == 0 || strcmp(optarg, "cdna") == 0) {
 				k = 15, w = 5;
 				opt.flag |= MM_F_SPLICE | MM_F_SPLICE_FOR | MM_F_SPLICE_REV;
diff --git a/minimap.h b/minimap.h
index e345915..def9640 100644
--- a/minimap.h
+++ b/minimap.h
@@ -19,6 +19,7 @@
 #define MM_F_SPLICE_REV  0x200
 #define MM_F_SPLICE_BOTH 0x400
 #define MM_F_NO_SAM_SQ   0x800
+#define MM_F_SR          0x1000
 
 #define MM_IDX_MAGIC   "MMI\2"