Complex sentence: Opening three card suits was also an obvious exposure in competition while the Roman bidders used a negative double only so far as 1S over their 1C opening, and not elsewhere, making the balanced structure also vulnerable to interference.
Split into simpler sentences: Opening three card suits was also an obvious exposure in competition. The Roman bidders used a negative double only so far as 1S over their 1C opening, and not elsewhere, making the balanced structure also vulnerable to interference.