Semi-Slav Defense
1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6
The Semi-Slav meets the Queen's gambit by playing both ...e6 and ...c6. Black then can complete his development and gain the chance for a later ...dxc4 followed by ...b5 and ...Bb7.
Pros:
- Sharp, but with solid foundations
- Focuses on the center
Cons:
- The light-squared bishop is temporarily blocked
- Very theoretical
- Can be avoided in various ways