We consider the question of how knots and their reverses are related in the concordance group
C
\mathcal {C}
. There are examples of knots for which
K
≠
K
r
∈
C
K \ne K^r \in \mathcal {C}
. This paper studies the cobordism distance,
d
(
K
,
K
r
)
d(K, K^r)
. If
K
≠
K
r
∈
C
K \ne K^r \in \mathcal {C}
, then
d
(
K
,
K
r
)
>
0
d(K, K^r) >0
and it is elementary to see that for all
K
K
,
d
(
K
,
K
r
)
≤
2
g
4
(
K
)
d(K, K^r) \le 2g_4(K)
, where
g
4
(
K
)
g_4(K)
denotes the four-genus. Here we present a proof that for non-slice knots satisfying
g
3
(
K
)
=
g
4
(
K
)
g_3(K) = g_4(K)
, one has
d
(
K
,
K
r
)
≤
2
g
4
(
K
)
−
1
d(K,K^r) \le 2g_4(K) -1
. This family includes all strongly quasi-positive knots and all non-slice genus one knots. We also construct knots
K
K
of arbitrary four-genus for which
d
(
K
,
K
r
)
=
g
4
(
K
)
d(K,K^r) = g_4(K)
. Finding knots for which
d
(
K
,
K
r
)
>
g
4
(
K
)
d(K,K^r) > g_4(K)
remains an open problem.